Mat 11:15 He who has ears to hear, let him hear.

Echo ("have," "hold) ous ("ear") akouo ("to hear") akouo ("to hear")

The word for "to hear," akouô, means "to hear," "to listen," "to obey," and "to understand."

The verse contrasts the two meanings of akouo. Christ is saying, "You have ear to hear, so understand and obey."