The Collaborative International Dictionary of English v.0.48:

Freewheel \Free"wheel`\, v. i.
   1.
      (a) Of a freewheel cycle, to run on while the pedals are
          held still.
      (b) Of a person, to ride a cycle of this manner; to coast
          in a vehicle having a freewheel. To ride a freewheel
          cycle. [WordNet sense 2]
          [Webster 1913 Suppl.]

   2. (Mach.) To operate like a freewheel, so that one part
      moves freely over another which normally moves with it; --
      said of a clutch.
      [Webster 1913 Suppl.]

   3. To act without controls, external or internal; to live
      freely, independently, and without concern; -- of people.
      [WordNet sense 1]
      [PJC]

The Collaborative International Dictionary of English v.0.48:

Freewheel \Free"wheel`\, n. (Mach.)
   A clutch fitted in the rear hub of a cycle, which engages the
   rear sprocket with the rear wheel when the pedals are rotated
   forwards, but permits the rear wheel to run on free from the
   rear sprocket when the pedals are stopped or rotated
   backwards. Freewheelcycles are usually fitted with hub brakes
   or rim brakes, operated by back pedaling.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

freewheel
    n 1: a clutch (as on the rear wheel of a bicycle) that allows
         wheels to turn freely (as in coasting)
    v 1: live unhurriedly, irresponsibly, or freely; "My son drifted
         around for years in California before going to law school"
         [syn: freewheel, drift]
    2: coast in a vehicle using the freewheel