observation (careful or controlled attention or consideration) / observation (the result of such attention or consideration) / observation (process of detached, objective examination) / observation (the result of one of the above-described actions expressed in or rendered into words for the purpose of dissemination) / observance of (adherence or conformity to) rules, conventions, laws, etc. / observance (performance) of religious rituals, customs, traditions, etc.

observance

present participle of observer

observable

to observe, watch / to note, notice / to keep, maintain

plural of observation

plural of observable

plural of observance