What does "chap" mean?

Additional senses

1. 2.To crack or open in slits; as, the earth chaps; the hands chap.
2. 3.To strike; to knock; to rap. [Scot.]
3. 4.A cleft, crack, or chink, as in the surface of the earth, or in the skin.
4. 5.A division; a breach, as in a party. [Obs.] Many clefts and chaps in our council board. T. Fuller.
5. 6.A blow; a rap. [Scot.]
6. 7.One of the jaws or the fleshy covering of a jaw; -- commonly in the plural, and used of animals, and colloquially of human beings. His chaps were all besmeared with crimson blood. Cowley. He unseamed him [Macdonald] from the nave to the chaps. Shak.
7. 8.One of the jaws or cheeks of a vise, etc.
8. 9.A buyer; a chapman. [Obs.] If you want to sell, here is your chap. Steele.
9. 10.A man or boy; a youth; a fellow. [Colloq.]
10. 11.To bargain; to buy. [Obs.]