What does "take it" mean?

Understand, as in I take it they won't accept your proposal. [Early 1500s]

Endure abuse, criticism, harsh treatment, or unpleasantness, as in Tell me what you really think of me—I can take it. [Mid-1800s] This phrase is sometimes modified as take just so much, meaning “endure only up to a point.” For example, I can take just so much of this nonsense before I lose patience. Also see take it on the chin; take lying down.

Accept or believe something, as in I'll take it on the doctor's say-so. Also see the subsequent entries beginning with take it.