The Collaborative International Dictionary of English v.0.48:

hook-and-ladder truck \hook"-and-lad"der truck\, hook and ladder
truck \hook" and lad"der truck\, hook and ladder \hook" and
lad"der\, n.
   A firefighting truck equipped with a ladder extendable to
   great length, for access to the upper stories of buildings;
   it also carries other firefighting equipment; called also
   ladder truck.
   [PJC]

The Collaborative International Dictionary of English v.0.48:

ladder company \ladder company\, ladder truck \ladder truck\n.
   Same as hook-and-ladder company, hook-and-ladder truck.
   [PJC]

WordNet (r) 3.0 (2006):

ladder truck
    n 1: a fire engine carrying ladders [syn: ladder truck,
         aerial ladder truck]