The Oxford Thesaurus An A-Z Dictionary of Synonyms - observe v.

1) obey, abide by, comply with, be heedful of, attend to, conform to, regard, keep, follow, adhere to, respect, pay attention to: We observed the prohibition against swimming. 2) watch, look at, examine, monitor, scrutinize, study, regard, view, inspect, pore over, contemplate, consider , Colloq check (out or up on) , check over, size up, Slang case: The naturalists went to the Arctic to observe the polar bears. 3) see, mark, notice, look, perceive: Observe how swiftly the skin forms pustules when this substance is applied. 4) Sometimes, observe on or upon. comment (on or upon) , remark (on or upon) , mention, say, note, refer (to) , make reference to, animadvert on or upon or to; state, declare: It is impolite to observe on others' manners. He couldn't help observing to his cell-mate how easy it would be to escape. 5) celebrate, keep, solemnize, respect, keep holy, mark, commemorate, memorialize, remember, recognize: We always observe the sabbath.