verb

1. To grasp a concept fully and thoroughly, especially (of words, statements, art, etc.) to be aware of the meaning of and (of people) to be aware of the intent of.

   “I'm sorry. I don't understand.”

2. To believe, to think one grasps sufficiently despite potentially incomplete knowledge.

   “I understand that you have a package for me?”

3. (obsolete outside circus, acrobatics) To stand underneath, to support.

Synonyms: believe, apprehend, comprehend, grasp, grok, know, perceive, pick up what someone is putting down