From The Collaborative International Dictionary of English v.0.48:
Buckle \Buc"kle\, v. t. [imp. & p. p. Buckled; p. pr. & vb. n.
Buckling.] [OE. boclen, F. boucler. See Buckle, n.]
1. To fasten or confine with a buckle or buckles; as, to
buckle a harness.
[1913 Webster]
2. To bend; to cause to kink, or to become distorted.
[1913 Webster]
3. To prepare for action; to apply with vigor and
earnestness; -- formerly, generally used reflexively, but
by mid 20th century, usually used with down; -- as, the
programmers buckled down and worked late hours to finish
the project in time for the promised delivery date.
[1913 Webster +PJC]
Cartwright buckled himself to the employment.
--Fuller.
[1913 Webster]
4. To join in marriage. [Scot.] --Sir W. Scott.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Buckle \Buc"kle\, n. [OE. bocle buckle, boss of a shield, OF.
bocle, F. boucle, boss of a shield, ring, fr. L. buccula a
little cheek or mouth, dim. of bucca cheek; this boss or knob
resembling a cheek.]
1. A device, usually of metal, consisting of a frame with one
more movable tongues or catches, used for fastening things
together, as parts of dress or harness, by means of a
strap passing through the frame and pierced by the tongue.
[1913 Webster]
2. A distortion bulge, bend, or kink, as in a saw blade or a
plate of sheet metal. --Knight.
[1913 Webster]
3. A curl of hair, esp. a kind of crisp curl formerly worn;
also, the state of being curled.
[1913 Webster]
Earlocks in tight buckles on each side of a lantern
face. --W. Irving.
[1913 Webster]
Lets his wig lie in buckle for a whole half year.
--Addison.
[1913 Webster]
4. A contorted expression, as of the face. [R.]
[1913 Webster]
'Gainst nature armed by gravity,
His features too in buckle see. --Churchill.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Buckle \Buc"kle\ (b[u^]k"k'l), v. i.
1. To bend permanently; to become distorted; to bow; to curl;
to kink.
[1913 Webster]
Buckled with the heat of the fire like parchment.
--Pepys.
[1913 Webster]
2. To bend out of a true vertical plane, as a wall.
[1913 Webster]
3. To yield; to give way; to cease opposing. [Obs.]
[1913 Webster]
The Dutch, as high as they seem, do begin to buckle.
--Pepys.
[1913 Webster]
4. To enter upon some labor or contest; to join in close
fight; to struggle; to contend.
[1913 Webster]
The bishop was as able and ready to buckle with the
Lord Protector as he was with him. --Latimer.
[1913 Webster]
In single combat thou shalt buckle with me. --Shak.
[1913 Webster]
To buckle to, to bend to; to engage with zeal.
[1913 Webster]
To make our sturdy humor buckle thereto. --Barrow.
[1913 Webster]
Before buckling to my winter's work. --J. D.
Forbes.
[1913 Webster]