WordNet (r) 3.0 (2006):

kibitz
    v 1: make unwanted and intrusive comments [syn: kibitz,
         kibbitz]

Moby Thesaurus II by Grady Ward, 1.0:

27 Moby Thesaurus words for "kibitz":
   Paul-Pry, advise, advocate, brief, busybody, coach, confer,
   consult with, counsel, direct, fool with, guide, instruct,
   intermeddle, meddle, meddle with, mess with, monkey with, nose,
   prescribe, propose, pry, recommend, snoop, submit, suggest,
   tamper with