From WordNet (r) 3.0 (2006):
understand
v 1: know and comprehend the nature or meaning of; "She did not
understand her husband"; "I understand what she means"
2: perceive (an idea or situation) mentally; "Now I see!"; "I
just can't see your point"; "Does she realize how important
this decision is?"; "I don't understand the idea" [syn:
understand, realize, realise, see]
3: make sense of a language; "She understands French"; "Can you
read Greek?" [syn: understand, read, interpret,
translate]
4: believe to be the case; "I understand you have no previous
experience?" [syn: understand, infer]
5: be understanding of; "You don't need to explain--I
understand!" [syn: sympathize, sympathise, empathize,
empathise, understand]