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.

present participle of observe

observation

plural of observation

Relating to observation, especially scientific observation.

(degree) To a detectable degree, sufficient to be observed. / (manner) In an observable manner. / (modal) Indicates that the proposition can be verified by observation.

plural of observable

plural of observance

(obsolete) An observer.