v. 25B6; verb
she observed that all the chairs were occupied : NOTICE, see, note, perceive, discern, spot; poetic/literary espy, descry.
she was alarmed to discover he had been observing her : WATCH, look at, eye, contemplate, view, survey, regard, keep an eye on, scrutinize, keep under observation, keep watch on, keep under surveillance, monitor, keep a weather eye on; informal keep tabs on, keep a beady eye on; poetic/literary behold.
You look tired, she observed : REMARK, comment, say, mention, declare, announce, state, pronounce; formal opine.
both countries agreed to observe the ceasefire : COMPLY WITH, abide by, keep, obey, adhere to, heed, honour, fulfil, respect, follow, consent to, acquiesce in, accept.
townspeople observed the one-year anniversary of the flood : COMMEMORATE, mark, keep, memorialize, remember, celebrate.