observant

adj. paying attention; watching; noticing; keeping religious laws; meticulous

Adjective
1. paying close attention especially to details
(similar) attentive
2. quick to notice; showing quick and keen perception
(synonym) observing
(similar) perceptive
3. (of individuals) adhering strictly to laws and rules and customs; "law-abiding citizens"; "observant of the speed limit"
(synonym) law-abiding
(similar) lawful

v. observe, watch; examen; notice, comment, remark; adhere, keep, respect, obey

n. observant, paying attention; watching; noticing; keeping religious laws; meticulous

(n.)
One who observes forms and rules.
  

(n.)
An Observantine.
  

(n.)
A sycophantic servant.
  

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

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