'blast off' definitions:

Definition of 'blast off'

(from WordNet)
verb
Launch with great force; "the rockets were blasted off"

Definition of 'blast off'

From: GCIDE
  • blast off \blast" off\ v. i. to begin ascending from the ground under rocket power; -- of a rocket. [PJC]

Synonyms of 'blast off'

From: Moby Thesaurus