noun
(uncountable) The act of one that understands or comprehends; the mental process of discernment of meaning.
(countable) Reason or intelligence; ability to grasp the full meaning of knowledge; ability to infer.
(countable) Opinion, judgement, or outlook.
(countable) An agreement of minds; harmony; something mutually understood or agreed upon.
(uncountable) Sympathy.
adjective
Showing compassion, tolerance, and forbearance; sympathetically aware.
(dated) Knowing; skilful.
verb
present participle and gerund of understand