“understand” – English explanatory dictionary

verb 1. to know what something means ○ Don’t try to talk English to Mr Yoshida – he doesn’t understand it. □ to make yourself understood to explain what you want, even if you don’t speak the language ○ I hardly speak any Japanese, but I managed to make myself understood. 2. to have information, to think something is true because someone has told you so ○ We understand that they’re getting married next month. ○ It was understood that the group would meet at the pub. 3. to have sympathy for someone ○ She’s a good teacher – she really understands children. 4. to know why something happens or how something works ○ I can easily understand why his wife left him. ○ I still don’t understand how to operate the new laser printer.

(un•der•stand´), v. t. [imp. & p. p. Understood , and Archaic Understanded; p. pr. & vb. n. Understanding.] [OE. understanden, AS. understandan, literally, to stand under; cf. AS. forstandan to understand, G. verstehen. The development of sense is not clear. See Under, and Stand.]
1. To have just and adequate ideas of; to apprehended the meaning or intention of; to have knowledge of; to comprehend; to know; as to understand a problem in Euclid; to understand a proposition or a declaration; the court understands the advocate or his argument; to understand the sacred oracles; to understand a nod or a wink. “Speaketh [i. e., speak thou] so plain at this time, I you pray,
That we may understande what ye say.” Chaucer. “I understand not what you mean by this.” Shak. “Understood not all was but a show.” Milton. “A tongue not understanded of the people.” Bk. of Com. Prayer.
2. To be apprised, or have information, of; to learn; to be informed of; to hear; as I understand that Congress has passed the bill.
3. To recognize or hold as being or signifying; to suppose to mean; to interpret; to explain. “The most learned interpreters understood the words of sin, and not of Abel.” Locke.
4. To mean without expressing; to imply tacitly; to take for granted; to assume. “War, then, war,
Open or understood, must be resolved.” Milton.
5. To stand under; to support. [Jocose & R.] Shak. To give one to understand, to cause one to know. — To make one’s self understood, to make one’s meaning clear.

v. i. 1. To have the use of the intellectual faculties; to be an intelligent being. “Imparadised in you, in whom alone
I understand, and grow, and see.” Donne.
2. To be informed; to have or receive knowledge. “I came to Jerusalem, and understood of the evil that Eliashib did for Tobiah.” Neh. xiii. 7.