1.  handler(n = noun.person) animal trainer - one who trains or exhibits animals;
Derived form verb handle₆

2.  handler(n = noun.person) - an agent who handles something or someone; "the senator's campaign handlers"
Derived form verb handle₁

3.  handler(n = noun.person) coach, manager - (sports) someone in charge of training an athlete or a team;
Derived form verb handle₆

1.  one who trains or exhibits animals. [WordNet 1.5]

2.  someone in charge of training an athlete (especially a boxer) or a team.

handler, n.
1 a person who handles or deals in certain commodities.
2 a person who trains and looks after an animal (esp. a police dog).