memo

noun

1. A short note; a memorandum.

   “According to yet another leaked memo, Powell responded the next day. Powell's leaked memo conceded that al Qaeda were not POWs, and that the Taliban individually or as a group might also lose their entitlement to that status.”

2. A record of partial results that can be reused later without recomputation.

   “The first is that the recursive call finds its subproblem solution in the memo and returns immediately.”

verb

1. (informal)To record something; to make a note of something.
2. (informal)To send someone a note about something, for the record.

   “I made sure to memo him about the client's complaints.”