'observance' definitions:

Definition of 'observance'

From: WordNet
noun
The act of observing; taking a patient look [syn: observation, observance, watching]
noun
A formal event performed on a special occasion; "a ceremony commemorating Pearl Harbor" [syn: ceremony, ceremonial, ceremonial occasion, observance]
noun
The act of noticing or paying attention; "he escaped the notice of the police" [syn: notice, observation, observance]
noun
Conformity with law or custom or practice etc. [syn: honoring, observance] [ant: nonobservance]

Synonyms of 'observance'

From: Moby Thesaurus