WordNet (r) 3.0 (2006):

call in
    v 1: summon to enter; "The nurse called in the next patient"
    2: summon to a particular activity or employment; "Experts were
       called in"
    3: pay a brief visit; "The mayor likes to call on some of the
       prominent citizens" [syn: visit, call in, call]
    4: take a player out of a game in order to exchange for another
       player
    5: make a phone call; "call in to a radio station"; "call in
       sick"
    6: demand payment of (a loan); "Call a loan" [syn: call, call
       in]
    7: cause to be returned; "recall the defective auto tires"; "The
       manufacturer tried to call back the spoilt yoghurt" [syn:
       recall, call in, call back, withdraw]

Moby Thesaurus II by Grady Ward, 1.0:

67 Moby Thesaurus words for "call in":
   advise with, ask, bargain, bid come, bill, call, call away,
   call back, call for, call forth, call out, call together, call up,
   cite, collogue, compare notes, confer, confer with, conjure,
   conjure up, consult, consult with, convene, convoke, counsel,
   deliberate, demand, demand payment, discuss, discuss with, dun,
   evoke, exchange observations, exchange views, have conversations,
   invite, invoice, invoke, issue an invitation, muster, muster up,
   negotiate, order up, page, palaver, parley, powwow, preconize,
   put heads together, reason with, recall, refer to, requisition,
   send a statement, send after, send for, serve, sit down together,
   sit down with, subpoena, summon, summon forth, summon up, summons,
   take counsel, take up with, talk over