Is there a word to refer to a character in a play or movie or a TV or radio show who is talked about but never actually shows up on stage or screen? The classic example would be Godot, but Colombo's wife would be another.
That seems to be the term of choice - and here's a list of a bunch of 'em. Niles Crane's ex-wife on Frasier popped to mind for me...
http://en.wikipedia.org/wiki/Unseen_character
Dear Faldage: I found a fairly long article called "Absent Fatso" which never used a term for the stagecraft bit.
http://pages.ivillage.com/mmorand2003/id8.html
How about disappearing characters. Is there a term for them?
For example, On The 70's show's first episodes, Donna has a pesky younger sister. She quickly gets written out of the show and Donna becomes and only child.
I know I've seen this happen in other shows too.
I can't put my finger on it right now but there was something similar that happened with The Torklesons (spelling may be off). I think a little brother was eliminated when they moved - or something of the sort.
Darn darn darn - can't remember the name of the movie but the first wife in the oldie ---was it Mayerling?
Then there is Laura in movie of same name. Starred Gene Tierney and Dana Andrews. Andrews plays a detective investigating Laura's murder and falling in love with her from what he learns and from a portrait. Then she show up! Good movie, stands up well - consider it if you need to rent something at the video store.
There's Sam Spade's dead partner Archer in The Maltese Falcon. Is the Thin Man seen or not?
In reply to:
How about disappearing characters. Is there a term for them?
Yeah. Unemployed actors. See also, waiters. 
Faldage, I thought you'd never ask! Why didn't I think of this?
The thin man is killed before the movie starts IIRC but he is seen in flashbacks.
Oh, that list from F'babe! The very first on the list is Abigail's Party. A play by Mike Leigh (I had forgotten that - thought it was Alan Ayckbourn). Once seen never forgotten, and yet it's comic (some might say tragi-comic). Abigail, whom you never see, is the daughter of one of the couples in the play and is giving a party in the next door apartment while the parents all get together, I guess waiting to take their teenage offspring home afterwards. The vitriol and social/sexual ruthlessness of their conversation and behaviour surpasses Updike at his worst! Theatre of mental cruelty. If you haven't seen it and it comes your way, don't miss it. I think the characters are recognisable right across the 'developed' world. I reckon ancient Egyptians, Greeks and Romans would have known them.
Channel Four's reviewer said: "Abigail's Party still ranks as the most painful hundred minutes in British comedy-drama."
Speaking of mental cruelty, I didn't see this one on the list: the son in "Who's Afraid of Virginia Woolf?".
the son in "Who's Afraid of Virginia Woolf?".
Not only mentioned but never on screen, but also not even existing.
Hope I didn't ruin the movie for anyone
Or "The Women" a fabulous old black-and-white about women's relationnships to each other and to the men around them. But the men never appear on screen.
The original movie of "The Women" based on the play by Clare Booth Luce was great. It starred Norma Shearer, Joan Crawford and Rosalind Russell !
The TV re-make was dreck.
Another disappearing sibling: Richie Cunningham's older brother, Chuck, on Happy Days. Although, on reflection, disappearing without a trace was the better fate.
Huh, I hadn't been aware there was an older brother.
I wonder if it's a reaction the producers get in the 'pilot' of a show. If the audience really doesn't like a character - off he goes and never existed.
I know I've seen several shows where the characters stay but the actor playing that character changes.
Very well known are the two Darrens on Bewitched and the switch of Becky in The Roseane Show.
I liked the Roseanne episode where they were talking about changing the actor on Bewitched (didn't they change the character's name, too?) laughing at them for thinking that nodoby would notice. This was just after they had gotten a new actress to play Becky. They also did something else that called attention to the change of actresses, either some comment about her (the character, Becky) not seeming like the same person or some comment when the original actress came back (or was that just sawdust in my JDM®?).
I remember that episode Faldage. The new Becky said she like the new Darren better.
Did the original Becky come back? I don't remember that. It seems like the new Becky was the one at the table when Roseanne said all her life since Dan's heart attack had been fiction, and she described what really happened to all the characters (i.e. Dan hadn't really survived the heart attach, her mom wasn't really gay, it was her sister that was...)
it was her sister that was
Well, we knew that.
The Chuck Cunningham character was around for more than the pilot. He was not present often in the story line, but several times referred to (he was away at college, on a basketball scholarship, IIRC). Chuck appeared on screen occasionally in the first two years of the show. Some time after that, Chuck disappeared into the TV ether.
Chuck was played by two actors (tying into the replacement actors branch of this thread ...): Gavan O'Herlihy and Randolph Roberts.
Let's not forget, perhaps, the most famous unseen character of all, the pookah rabbit Harvey in, of course,
Harvey. (and another fine Jimmy Stewart performance)
The Darrin Stephens character on Bewitched, played by Dick York and Dick Sargent, did not change names when the actors changed.
As for Becky Conner on Rosanne: Lecy Goranson played her from 1988-1992, Sarah Chalke played her 1993-1995, Goranson and Chalke alternated (!?!) 1995-1996, and Chalke played her 1996-1997.
Another show that drew attention to the switching of actors to play the same character is "Due South". It's about a Mountie working in Chicago. At one point, the actor playing his Chicago Police Dept partner switched from a somewhat frumpy dark-haired man to a (in my opinion) very handsome but somewhat ragged blond guy. I forget exactly how they dealt with it -- the new guy went undercover as the old guy or something. But I think he was reluctant to do so, and couldn't figure out why everyone was calling him by the old character's name. I wish I could recall more -- I do remember laughing a LOT when I saw it.
I remember that show. Rather liked it; stereotypical Dudley Do Right mountie in the cold cruel big city. Don't remember the actor shift, seems like they could've handled it just by assigning a new character to the role of being the mountie's baby-sitter.
Faldage, in the case of Godot, couldn't he be a Mcguffin?
I knew there was a neat recognition of the fact that Ray was played by a new actor:
"At the beginning of the second season, however, Fraser took a vacation in Canada, and came back to find that someone was impersonating his partner. In fact, Stanley Raymond Kowalski (played by Callum Keith Rennie) was taking Ray Vecchio's place while Ray was under cover, as was learned later that episode, from Lieutenant Welsh (portrayed by Beau Starr)."
from IMDB
http://www.imdb.com/title/tt0194607/plotsummary
Is there a word to refer to a character in a play ... who is talked about but never actually shows up on stage or screen?
Yes, such a character is known as a "stage sprite".
Some stage sprites are too scared to show up in which case they are said to have "stage fright".
But, a stage sprite with stage fright is not the norm. Usually they are just written out of the script.