WOTD: Doit

No, it’s not an elided part of a Nike commercial.

doit (n.) IPA Pronunciation: doit
small sum, worthless amount, trifle

Where they will will not give a doit to relieve a lame beggar…
– The Tempest (II.ii)

A doit was a small Dutch coin that was worth half an English farthing, which wasn’t much. So half of that (and perhaps the fact that it was Dutch) made it a worthless amount.