The act of observing, and the fact of being observed (see observance) / The act of noting and recording some event; or the record of such noting. / A remark or comment. / A judgement based on observing.

(transitive) To notice or view, especially carefully or with attention to detail. / (transitive) To follow or obey the custom, practice, or rules (especially of a religion).

(archaic) An observation (remark, comment or judgement).

Able to be observed. / Deserving to be observed; worth regarding; remarkable.

(physics) Any physical property that can be observed and measured directly and not derived from other properties

The practice of complying with a law, custom, command or rule. / The custom of celebrating a holiday or similar occasion. / Observation or the act of watching.

Alert and paying close attention; watchful. / Diligently attentive in observing a law, custom, duty or principle; regardful; mindful.

One who makes observations, monitors or takes notice / One who adheres or follows laws, guidelines, etc.

simple past tense and past participle of observe / (of a holiday) Exceptionally celebrated on a date other than the usual date.

present participle of observe