WordNet (r) 3.0 (2006):

account for
    v 1: be the reason or explanation for; "The recession accounts
         for the slow retail business"
    2: give reasons for; "Can you account for all these absences?"

Moby Thesaurus II by Grady Ward, 1.0:

80 Moby Thesaurus words for "account for":
   accredit with, accrete to, acknowledge, allegorize, apply to,
   ascribe to, assign to, attach to, attribute to, blame, blame for,
   blame on, bring home to, charge on, charge to, clarify, clear,
   clear up, confess, connect with, crack, credit with,
   cry sour grapes, decipher, demonstrate, demythologize,
   destigmatize, do justice to, elucidate, enlighten, euhemerize,
   exculpate, exemplify, explain, explain away, explicate, exposit,
   expound, fasten upon, father upon, fix on, fix upon,
   give reason for, give the meaning, hang on, illuminate, illustrate,
   impute to, justify, lay to, make clear, make plain, pin on,
   pinpoint, place upon, point to, popularize, purge, rationalize,
   refer to, rehabilitate, reinstate, restore, saddle on, saddle with,
   set down to, settle upon, shed light upon, show, show how,
   show the way, simplify, solve, spell out, throw light upon, unfold,
   unlock, unravel, vindicate, warrant