The definition of hearken is to listen carefully.(verb)
When you listen very carefully to advice given by your parents and you actually pay attention and consider what they are saying, this is an example of a time when you hearken.
See hearken in Webster's New World College Dictionary
Origin: ME herknien < OE heorknian, hyrcnian < base of hieran: see hear
See hearken in American Heritage Dictionary 4
also har·kenverb hear·kened also har·kened, hear·ken·ing also har·ken·ing, hear·kens also har·kens verb, intransitive
Origin: Middle English herknen
Origin: , from Old English hercnian; see kous- in Indo-European roots.
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