What does "knuckle" mean?

Roy Cooke sometimes writes in his books that he or so and so "knuckled." I'm not finding this in any poker glossaries. Is it the same as call?

[Jimbo]

It means call when you are in the BB, or have posted late and it is still only one bet to you. Often this closes all the action since it normally occurs in the BB.

Jimbo

[eMarkM]

Planet Poker's definition:

knuckle

1. (v) stand pat. 2. (n) The act of standing pat. "He gave it the knuckle" means he drew no cards. So called because a player, if he has a pat hand, often raps on the table with his knuckles when it is his turn to announce his draw. Also, knock, rap.

[Jimbo]

I agree with the above definition in draw poker but this question was posed as a Texas Holdem question.

Jimbo

[baggins]

its the same as tapping or patting the felt insteaed of saying 'check'. note that this action is frequently done with the knuckle being the part of the hand that actually makes contact with the table or felt, thus the term 'knuckling'.