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.

plural of observation

Relating to observation, especially scientific observation.

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

plural of observability

Obsolete form of observance.

observant; watchful

plural of observance

(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