Definition of load up:
(v) :
(transitive) To fill (a vehicle, vessel, room, etc.) with a load of cargo or similar.
(v) :
(transitive) To load (things) as cargo or similar.
(v) :
(intransitive) To receive a load of cargo or similar.
(v) :
(computing, ambitransitive) To load (software) fully into memory.
(v) :
(idiomatic, ambitransitive) To fully load (a weapon).
(v) :
(intransitive, slang) To intoxicate oneself with alcohol or drugs; to get drunk or get high.