Observant

1. One who observes forms and rules.
2. A sycophantic servant.
3. Submissively attentive; obediently watchful; regardful; mindful; obedient (to); -- with of, as, to be observant of rules.
4. An Observantine.
5. Taking notice; viewing or noticing attentively; watchful; attentive; as, an observant spectator; observant habits.