[ob.ser.vant] adj (1602) 1 a: paying strict attention: watchful "an ~ spectator" b: keen, perceptive
2: careful in observing (as rites, laws, or customs): mindful "pious and religiously ~ families --Sidney Hook" "always ~ of the amenities" -- ob.ser.vant.ly adv
[2]observant n (1605) obs: an assiduous or obsequious servant or attendant