to listen attentively; hearken.

Archaic . to listen to; hear.

a hunter's shout to hounds, as to encourage them in following the scent. ?

hark back,

(of hounds) to return along the course in order to regain a lost scent.

to return to a previous subject or point; revert

He kept harking back to his early days in vaudeville.

verb

pay attention , give heed , listen , attend , heed , hearken , hear , notice , obey , whisper