1. ability to grasp meaning: the ability to perceive and explain the meaning or the nature of somebody or something
2. knowledge of something: knowledge of a particular subject, area, or situation gaining a better understanding of industrial processes
3. interpretation of something: somebody's interpretation of something, or a belief or opinion based on an interpretation of or inference from something It was my understanding that the costs would be shared equally.
4. mutual comprehension: an agreement, often an unofficial or unspoken one I'm sure we can come to an understanding about this.
5. knowledge of another's nature: a sympathetic, empathetic, or tolerant recognition of somebody else's nature or situation I thought you of all people would show a little understanding.
adjective
Definition:
sympathetically aware: sympathetic, empathetic, or tolerant in recognizing somebody's or something's character and situation fortunate in having understanding parents