Definition of "Understand" :

verb: know and comprehend the nature or meaning of

"She did not understand her husband."

verb: perceive (an idea or situation) mentally

"I don't understand the idea."

verb: believe to be the case

"I understand you have no previous experience?."

verb: make sense of a language

"She understands French."

verb: be understanding of

"You don't need to explain--I understand!."