Definition of "jowl"

I had lain, therefore, all that time, cheek by jowl with Blackbeard himself, with only a thin shell of tinder wood to keep him from me, and now had thrust my hand into his coffin and plucked away his beard.

1898, J. Meade Falkner, chapter 4, in Moonfleet, London, Toronto, Ont.: Jonathan Cape, published 1934

That ſkull had a tongue in it, and could ſing once, how the knave iowles it to the ground, as if twere Caines iawbone, that did the firſt murder, this might be the pate of a pollitician, which this aſſe now ore-reaches; one that would circumuent God, might it not?That skull had a tongue in it, and could sing once – how that knave [a gravedigger] throws it to the ground, as if it was the jawbone of Cain, who committed the first murder. This might have been the head of a politician, which this ass now gets the better of; one that could have talked its way around God, might it not?

c. 1599–1602 (date written), William Shakespeare, The Tragicall Historie of Hamlet, Prince of Denmarke: […] (Second Quarto), London: […] I[ames] R[oberts] for N[icholas] L[ing] […], published 1604, [Act V, scene i]