The Collaborative International Dictionary of English v.0.48:

check out \check` out"\ v. i.
   1. To vacate a room at a hotel, notel, etc. Converse of
      check in.
      [PJC]

   2. To die. [Colloq.]
      [PJC]

The Collaborative International Dictionary of English v.0.48:

check out \check" out\ v. t.
   1. To inspect or examine. [Colloq.]
      [PJC]

   2. To make a record of having borrowed (something) for
      temporary use; as, to check out a book at the library; to
      check out equipment from a depository.
      [PJC]

   3. To bring (items to be purchased) to a checkout counter
      (as at a supermarket or other retail store) where the
      prices may be totaled and the bill may be paid.
      [PJC]

WordNet (r) 3.0 (2006):

check out
    v 1: examine so as to determine accuracy, quality, or condition;
         "check the brakes"; "Check out the engine" [syn: check,
         check up on, look into, check out, suss out, check
         over, go over, check into]
    2: announce one's departure from a hotel [ant: check in, sign
       in]
    3: be verified or confirmed; pass inspection; "These stories
       don't check!" [syn: check, check out]
    4: trace; "We are running down a few tips" [syn: run down,
       check out]
    5: record, add up, and receive payment for items purchased; "She
       was checking out the apples that the customer had put on the
       conveyer belt"
    6: withdraw money by writing a check [syn: cheque, check
       out]
    7: try to learn someone's opinions and intentions; "I have to
       sound out the new professor" [syn: check out, sound out,
       feel out]