/hahrk/ , v.i.
1. to listen attentively; hearken.
v.t.
2. Archaic. to listen to; hear.
3. hark back ,
a. (of hounds) to return along the course in order to regain a lost scent.
b. to return to a previous subject or point; revert: He kept harking back to his early days in vaudeville.
n.
4. a hunter's shout to hounds, as to encourage them in following the scent.
[ 1175-1225; ME herken, earlier herkien, OE * heorcian; c. OFris herkia, harkia; akin to MD harken, MHG, G horchen. See HEARKEN; HEAR ]
Syn. 3b . refer, allude; regress, retrogress.