What is the main action described by the verb 'glean'?

The verb 'glean' primarily refers to the act of collecting information or materials gradually and bit by bit, often after the main harvest or collection has taken place. This term has its roots in agricultural practices where gleaners would follow harvesters to pick up leftover crops. In a broader sense, it can be applied to gathering insights, knowledge, or data slowly and meticulously from various sources, reflecting a careful and selective approach.

This definition aligns with the answer that specifically highlights the gradual and piecemeal nature of the action described by 'glean.' The other options do not capture the essence of this process. For instance, gathering randomly does not convey the intentional and careful manner in which gleaning occurs, while discarding unnecessary information and summarizing quickly are separate actions that do not relate to the concept of gradual collection. Thus, the choice that emphasizes the gradual and thorough collection perfectly encapsulates the meaning of 'glean.'