Today being Good Friday it was brought to my attention once again that the plaque in our church's Stations of the Cross reads "Jesus is laid in the sepulchre." I'm well-familiar with this as the word for tomb in the Biblical sense, but I've rarely heard it used to describe a tomb or entombment in modern society (as something of an archaicism). On looking it up out of curiosity I see there are many variations of this word-- nouns, verbs, adjectives, and spelling variations. The AHD says of sepulchre, the noun, that it is chiefly the British version of sepulcher...but I've always seen and spelled it -re through years of Catholic school and Catechism on these shores.

from Websters-Merriam:

Main Entry: 1sep·ul·chre
Variant(s): or sep·ul·cher /'se-p&l-k&r/
Function: noun
Etymology: Middle English sepulcre, from Old French, from Latin sepulcrum, sepulchrum, from sepelire to bury; akin to Greek hepein to care for, Sanskrit saparyati he honors
Date: 13th century
1 : a place of burial : TOMB
2 : a receptacle for religious relics especially in an altar <

>Main Entry: 2sepulchre
Variant(s): or sepulcher
Function: transitive verb
Inflected Form(s): -chred or -chered; -chring or sep·ul·chering /-k(&-)ri[ng]/
Date: 1591
1 archaic : to place in or as if in a sepulchre : BURY
2 archaic : to serve as a sepulchre for <

>Main Entry: se·pul·chral
Pronunciation: s&-'p&l-kr&l also -'pul-
Function: adjective
Date: 1615
: suited to or suggestive of a sepulchre : FUNEREAL, MORTUARY
- se·pul·chral·ly /-kr&-lE/ adverb <

>Main Entry: sep·ul·ture
Pronunciation: 'se-p&l-"chur
Function: noun
Etymology: Middle English, from Old French, from Latin sepultura, from sepultus, past participle of sepelire
Date: 14th century
1 : BURIAL
2 : SEPULCHRE

If I hear sepulchre colloquially at all anymore, it seems the usage favors the second part of the first definition, receptacle for religious relics especially in an altar,
but expanded to include larger areas, such as the baptismal sepulchre, or, in many cases, a larger room kept for a specific purpose of even secular nature...and sometimes it seems some folks use it (mistakenly or descriptively?) to describe a foyer in general.

My Latin dictionary defines sepultura as burial, funeral; sepulchrum is the tomb or grave. But we cain' spec them iggerunt modrens to keep them fine distincshuns.

I have a feeling the "sepulture" has elements of abstraction,
taking into considertation rites, and customs. A sepulcher
is just the hardware.

                    
     Alone, and yet alive!  Oh, sepulchre!
     My soul is still my body's prisoner!
     Remote the peace that Death alone can give--
     My doom, to wait! my punishment, to live!
     
               Hearts do not break!
               They sting and ache
               For old love's sake,
                    But do not die,
               Though with each breath
               They long for death
               As witnesseth
                    The living I!
                         Oh, living I!
                         Come, tell me why,
                         When hope is gone,
                         Dost thou stay on?
                         Why linger here,
                         Where all is drear?
                         Oh, living I!
                         Come, tell me why,
                         When hope is gone,
                         Dost thou stay on?
                    May not a cheated maiden die?
                    May not a cheated maiden die?

--Mikado, Act Two (right after "the Flowers that Bloom in the Spring [tra-la]"
sung by KATISHA, upon learning that her beloved Nanki-Poo has been "executed".

Gilbert seems to have meant the first part of the first definition: a place of entombment. (And buried alive, at that.) Nothing sacred or religious about it.