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

plural of observability

(uncountable) The state of being observable / (countable) A measure of the extent to which something is observable

observant; watchful

A member of a Franciscan order that strictly observes the rules of St. Francis.

plural of observancy

Obsolete form of observance.

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

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.