1. To gather slowly and laboriously, bit by bit: Etymologists glean their knowledge from many classical sources.
2. To learn, to discover, or to find out; usually little by little or slowly: As a freelance writer, Sharon is barely gleaning how to make a decent living.

Lawyers glean, or go through every piece of evidence they can find in order to defend their clients.

3. To gather (grain or similar plant products) after the reapers or regular gatherers have finished and whatever they have left behind: In some countries, people glean, or pick up left over scraps of wheat, maize, oats, etc. which are left after the main harvesting process is completed.
4. Etymology: from Old French glener, from Late Latin glennare "to make a collection".