[n] the capacity for rational thought or inference or discrimination; "we are told that man is endowed with reason and capable of distinguishing good from evil"
[n] the cognitive condition of someone who understands; "he has virtually no understanding of social cause and effect"
[n] the statement (oral or written) of an exchange of promises; "they had an agreement that they would not interfere in each other's business"; "there was an understanding between management and the workers"
[n] an inclination to support or be loyal to or to agree with an opinion; "his sympathies were always with the underdog"; "I knew I could count on his understanding"
[adj] characterized by understanding based on comprehension and discernment and empathy; "an understanding friend"