What is the meaning of Glean?

To collect what is left behind (grain, grapes, etc.) after the main harvest or gathering.

To gather what is left in (a field or vineyard).

To gather information in small amounts, with implied difficulty, bit by bit.

To frugally accumulate resources from low-yield contexts.

A collection made by gleaning.

cleaning; afterbirth

Eclipsed form of clean.

Source: wiktionary.org