............would appreciate ANY help on the origin of this word, thanks - it's one I have known all my life (may be something to do with my Scottish mum? :-)..........but now find I am being challenged to find it in a dictionary AND what its meaning is...........'officially'..............hopefully - Seona

Hi Seona, and welcome.

It would probably help if we knew the 'unofficial' meaning. More to the point, *I would like to know what it means, and for that matter, how it should be pronounced. The dictionary readers will be by shortly and I have no doubt they will be able to furnish you with an answer.

*I would like to know what it means

It'd be something like, "Skoosh a bug and you gits rain." I would spec it's just a dialect variant of squash, the verb, not the vegetable.

Welcome to you, Seona; but I'm afraid I can't help you with the origin. I am looking at it in a dictionary, though, that was given me by my good friend jmh.
skoosh, scoosh verb gush in spurts or splashes, squirt; dart or move quickly with a swishing sound.
noun 1 a splash, spurt, jet (of liquid). 2 lemonade etc.
adverb with a splash or swish.
skoosher a device for sprinkling or spraying, a sprinkler.

This is from the "Pocket Scots Dictionary", put out by the Scottish National Dictionary Association, isbn # 1-902930-02-9. (Note: having triple-checked, I feel safe in saying that I have been accurate in re-creating all punctuation.)

"Skoosh a bug and you gits rain." I would spec it's just a dialect variant of squash, the verb

Ah yes - heard this on occasion from Scottish friends. Think it's slightly more like squish than squash tho' (says he, teaching grandma how to squish nits )