(1):

(n.) An Observantine.

(2):

(a.) Taking notice; viewing or noticing attentively; watchful; attentive; as, an observant spectator; observant habits.

(3):

(a.) Submissively attentive; obediently watchful; regardful; mindful; obedient (to); - with of, as, to be observant of rules.

(4):

(n.) One who observes forms and rules.

(5):

(n.) A sycophantic servant.