all-out

adjective

1. Covering all aspects with painstaking accuracy: complete, exhaustive, full-dress, intensive, thorough, thoroughgoing, thoroughpaced. See big/small/amount, careful/careless.
2. Completely such, without qualification or exception: absolute, arrant, complete, consummate, crashing, damned, dead, downright, flat, out-and-out, outright, perfect, plain, pure, sheer, thorough, thoroughgoing, total, unbounded, unequivocal, unlimited, unmitigated, unqualified, unrelieved, unreserved, utter. Informal flat-out, positive. Chiefly British blooming. See big/small/amount, limited/unlimited.

Definition: complete
Antonyms: half-hearted, halfway

The adjective has one meaning:

Meaning #1: using all available resources
  Synonym: full-scale