Jack Sprat

Jack Sprat is a nursery rhyme with lyrics as follows:

Jack Sprat could eat no fat

His wife could eat no lean.

And so between the two of them,

They licked the platter clean!

The word between in the third line is alternatively seen as the word betwixt.

External sources

This site Suggests the possible derivation of the rhyme. I have not been able to substantiate it thus far.