The Collaborative International Dictionary of English v.0.48:

Pickup \Pick"up\, or Pick-up \Pick"-up`\, n. [Colloq., Cant, or
   Slang]
   1. Act of picking up, as, in various games, the fielding or
      hitting of a ball just after it strikes the ground.
      [Webster 1913 Suppl.]

   2. That which picks up; specif.: (Elec.) same as Brush b.
      [Webster 1913 Suppl.]

   3. One that is picked up, as a meal hastily got up for the
      occasion, a chance acquaintance, an informal game, etc.
      [Webster 1913 Suppl.]

   4. a social companion for the evening who is met without
      prior arrangement, as at a singles bar; also, the act of
      joining with such a companion in that fashion.
      [PJC]

   5. (Automobiles) acceleration; a measure of the ability of a
      vehicle to accelerate.
      [PJC]

   6. (Electronics) a component of a phonograph which contains
      the stylus and also components for converting the
      vibrations of the stylus into electrical impulses for
      subsequent processing into sound; often referred to as a
      cartridge; also, the process of converting vibrations
      into electrical impulses.
      [PJC]

   7. (Electronics) the conversion of sound or light into
      electrical signals in a sound or image recording or
      transmitting device.
      [PJC]

   8. (Vehicles) a small truck having an enclosed driver's
      compartment (cab) but an open rear with usually low sides
      and a tailgate. Also called pickup truck.
      [PJC]

   9. a hitchhiker who has been picked up.
      [PJC]

The Collaborative International Dictionary of English v.0.48:

Cartridge \Car"tridge\ (k[aum]r"tr[i^]j), n. [Formerly cartrage,
   corrupted fr. F. cartouche. See Cartouch.] (Mil.)
   A complete charge for a firearm, contained in, or held
   together by, a case, capsule, or shell of metal, pasteboard,
   or other material.
   [1913 Webster]

   Ball cartridge, a cartridge containing a projectile.

   Blank cartridge, a cartridge without a projectile.

   Center-fire cartridge, a cartridge in which the fulminate
      occupies an axial position usually in the center of the
      base of the capsule, instead of being contained in its
      rim. In the Prussian needle gun the fulminate is applied
      to the middle of the base of the bullet.

   Rim-fire cartridge, a cartridge in which the fulminate is
      contained in a rim surrounding its base.

   Cartridge bag, a bag of woolen cloth, to hold a charge for
      a cannon.

   Cartridge belt, a belt having pockets for cartridges.

   Cartridge box, a case, usually of leather, attached to a
      belt or strap, for holding cartridges.

   Cartridge paper.
   (a) A thick stout paper for inclosing cartridges.
   (b) A rough tinted paper used for covering walls, and also
       for making drawings upon.
       [1913 Webster]

WordNet (r) 3.0 (2006):

cartridge
    n 1: ammunition consisting of a cylindrical casing containing an
         explosive charge and a bullet; fired from a rifle or
         handgun
    2: a light-tight supply chamber holding the film and supplying
       it for exposure as required [syn: magazine, cartridge]
    3: a module designed to be inserted into a larger piece of
       equipment; "he loaded a cartridge of fresh tape into the tape
       deck"
    4: an electro-acoustic transducer that is the part of the arm of
       a record player that holds the needle and that is removable
       [syn: cartridge, pickup]

Moby Thesaurus II by Grady Ward, 1.0:

90 Moby Thesaurus words for "cartridge":
   Gramophone, PA, PA system, Victrola, audio sound system,
   audiophile, backing, ball cartridge, bibliofilm, binaural system,
   bipack, bitch box, black-and-white film, blank cartridge, bullhorn,
   cartouche, cassette, ceramic pickup, changer, color film,
   color negative film, crystal pickup, derived four-channel system,
   disc, discrete four-channel system, dope, dry plate,
   electrical transcription, emulsion, film,
   four-channel stereo system, frame, hi-fi, hi-fi fan, high-fidelity,
   intercom, intercommunication system, jukebox, magnetic pickup,
   microfilm, monaural system, mono, monochromatic film,
   motion-picture film, needle, negative, nickelodeon,
   orthochromatic film, pack, panchromatic film, phonograph,
   phonograph record, photoelectric pickup, photographic paper,
   pickup, plate, printing paper, public-address system,
   quadraphonic sound system, radio-phonograph combination, record,
   record changer, record player, recording, roll, shell, sound film,
   sound reproduction system, sound track, sound truck, sound-on-film,
   soundstripe, squawk box, stereo, stylus, system, tape,
   tape cartridge, tape cassette, tape deck, tape recorder,
   tape recording, tone arm, transcription, transcription turntable,
   tripack, turntable, vehicle, wax, wire recording