WordNet (r) 3.0 (2006):

checkbook
    n 1: a book issued to holders of checking accounts [syn:
         checkbook, chequebook]

Moby Thesaurus II by Grady Ward, 1.0:

39 Moby Thesaurus words for "checkbook":
   CD, IOU, MO, acceptance, acceptance bill, bank acceptance,
   bank check, bill, bill of draft, bill of exchange, blank check,
   certificate, certificate of deposit, certified check, check,
   cheque, commercial paper, debenture, demand bill, demand draft,
   draft, due bill, exchequer bill, letter of credit, money order,
   negotiable instrument, note, note of hand, paper, postal order,
   promissory note, sight bill, sight draft, time bill, time draft,
   trade acceptance, treasury bill, voucher, warrant