Definition of "jump on"

jump on

verb
third-person singular simple present jumps on, present participle jumping on, simple past and past participle jumped on
1. To board a vehicle.
2. (idiomatic) To attack verbally, to criticise excessively.
3. (idiomatic) To take immediate action regarding; to avail oneself of without delay.
  Quotations
  Community banks can jump on the opportunity to make changes.
  2003 October 28, “Banking Giant”, in New York Times, retrieved 15 June 2011
  So later in life, when the Z's — and even onetime Z's who became A's through marriage — see an item they really like for sale or are offered a deal, they jump on it.
  2011 January 28, “How Your Name May Cost You at the Mall”, in Time