I heard someone call his little girl 'squirt' a long time ago. I can remember who it was, and where, although not quite when, but I won't bore you with the details. Or reveal myself as the soap addict I really am. It struck me as cute. I never looked it up, but took it to mean something similar to 'chick pea' in its endearing form, 'shorty', with a bit of a naughty connotation.
I have recently found out that googling 'squirt' will not exactly lead you where I, in good conscience, would send you to look. Now don't say I didn't warn you ;-)
Googling 'squirt synonym' will get you closer to the truth - here are results from thesaurus.reference.com
Main entry: child, definition: very young person
Synonyms: anklebiter, babe, bairn, brat, cub, kiddie, lamb, little one, minor, mite, moppet, nipper, small fry, sprout, squirt, tadpole, toddler, tot, tyke, urchin, young one, youngster (and that's after I've taken the liberty of omitting some!).
Obviously I take offence to definitions containing phrases like 'person of little or no significance'. And I can't find proof for the slight bit of naughty. But since I haven't found proof to the contrary either, just consider it attached for this blog's purposes, okay? ;-)
P.S. Incidentally, Squirt is also the cute little turtle in 'Finding Nemo' - courtesy of Google. I must have known once, but forgot. When you consider that a turtle/tortoise (one word in Dutch) is the only animal Squirt wants to acknowledge by name these days ('patta'), his nickname is an apt little coincidence :-D