Iota and jot are the same thing, from the Greek iota subscript used in the dative case for nouns, it was originally the final character (as in oi or ai) but the scribes took to writing it underneath in a much smaller size, so iota subscript was the tiniest letter. It's used in the New Testament (Matthew 5:18, not one jot ... shall disappear from the law) - the jot was the iota subscript.Some of my favourite words for a small amount:
Smidgen, jot, iota, scintilla, modicum
Not really a unit of measurement but on the same vein as your's Norman. My wife uses the term bin bin to describe the outside bin, rather than the kitchen bin. Can you put that in the bin bin?The big light - Put the big light on for me.