1. (p. pr. & vb. n.) of Observe.

2. (a.) Giving particular attention; habitually attentive to what passes; as, an observing person; an observing mind.

agog alert all ears all eyes assiduous attentive aware careful concentrated conscious diligent earnest finical finicking finicky heedful intense intent intentive meticulous mindful nice niggling observant observing on the ball on the job open-eared open-eyed openmouthed regardful watchful