means The time that has already happened, everything that came before now.

from From Latin 'passus,' the past participle of 'pati' — to suffer or undergo — which gave Old French 'passer,' to pass or go by. English 'past' began life as a worn-down form of 'passed,' the time that has gone by us and slipped behind. So 'past' is literally what has already passed — a verb that froze into a noun, like a footprint left in the act of walking on.