transitive verb observed -·served′, observing -·serv′·ing

1. to adhere to, follow, keep, or abide by (a law, custom, duty, rule, etc.)
2. to celebrate or keep (a holiday, etc.) according to custom
3. 1. to notice or perceive (something)
   2. to pay special attention to
4. to arrive at as a conclusion after study
5. to say or mention casually; remark
6. to examine and study scientifically

Etymology: ME observen < OFr observer < L observare, to watch, note < ob- (see ob-) + servare, to keep or hold < IE base *ser-, to watch over, guard > Sans haraiti, (he) guards

intransitive verb

1. to take notice
2. to comment or remark (on or upon)
3. to act as an observer