The Collaborative International Dictionary of English v.0.48:

crook \crook\ (kr[oo^]k), n. [OE. crok; akin to Icel. kr[=o]kr
   hook, bend, SW. krok, Dan. krog, OD. krooke; or cf. Gael.
   crocan crook, hook, W. crwca crooked. Cf. Crosier,
   Crotchet, Crutch, Encroach.]
   1. A bend, turn, or curve; curvature; flexure.
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            Through lanes, and crooks, and darkness. --Phaer.
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   2. Any implement having a bent or crooked end. Especially:
      (a) The staff used by a shepherd, the hook of which serves
          to hold a runaway sheep.
      (b) A bishop's staff of office. Cf. Pastoral staff.
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                He left his crook, he left his flocks. --Prior.
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   3. A pothook. "As black as the crook." --Sir W. Scott.
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   4. An artifice; trick; tricky device; subterfuge.
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            For all yuor brags, hooks, and crooks. --Cranmer.
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   5. (Mus.) A small tube, usually curved, applied to a trumpet,
      horn, etc., to change its pitch or key.
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   6. A person given to fraudulent practices; an accomplice of
      thieves, forgers, etc. [Cant, U.S.]
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   By hook or by crook, in some way or other; by fair means or
      foul.
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The Collaborative International Dictionary of English v.0.48:

Crook \Crook\ (kr??k), v. t. [imp. & p. p. Crooked (kr??kt);
   p. pr. & vb. n. Crooking.] [OE. croken; cf. Sw. kr?ka, Dan.
   kr?ge. See Crook, n.]
   1. To turn from a straight line; to bend; to curve.
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            Crook the pregnant hinges of the knee. --Shak.
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   2. To turn from the path of rectitude; to pervert; to
      misapply; to twist. [Archaic]
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            There is no one thing that crooks youth more than
            such unlawfull games.                 --Ascham.
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            What soever affairs pass such a man's hands, he
            crooketh them to his own ends.        --Bacon.
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The Collaborative International Dictionary of English v.0.48:

Crook \Crook\, v. i.
   To bend; to curve; to wind; to have a curvature. " The port .
   . . crooketh like a bow." --Phaer.
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         Their shoes and pattens are snouted, and piked more
         than a finger long, crooking upwards.    --Camden.
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WordNet (r) 3.0 (2006):

crook
    n 1: someone who has committed a crime or has been legally
         convicted of a crime [syn: criminal, felon, crook,
         outlaw, malefactor]
    2: a circular segment of a curve; "a bend in the road"; "a crook
       in the path" [syn: bend, crook, twist, turn]
    3: a long staff with one end being hook shaped [syn: crook,
       shepherd's crook]
    v 1: bend or cause to bend; "He crooked his index finger"; "the
         road curved sharply" [syn: crook, curve]