What is "afterings"

Afterings \Aft"er*ings\, n. pl. The last milk drawn in milking; strokings. [Obs.]
--Grose.

n. 1 The last milk that is obtained when milking a cow. Often considered the poorest quality of milk. 2 (context by extension English) the last of any substance that is of a poorer quality than the earlier substance, e.g. the dregs of coffee.