absolutely required and not to be used up or sacrificed
absolutely necessary; vitally necessary; "essential tools and materials"; "funds essential to the completion of the project"; "an indispensable worker"
being or relating to or containing the essence of a plant etc; "essential oil"
an initial accomplishment that opens the way for further developments; "the town became a beachhead in the campaign to ban smoking outdoors"; "they are presently attempting to gain a foothold in the Russian market"
a bridgehead on the enemy's shoreline seized by an amphibious operation; "the Germans were desperately trying to contain the Anzio beachhead"
a defensive post at the end of a bridge nearest to the enemy
an area in hostile territory that has been captured and is held awaiting further troops and supplies; "an attempt to secure a bridgehead behind enemy lines"; "the only foothold left for British troops in Europe was Gibraltar"
the decisive moment in a novel or play; "the deathbed scene is the climax of the play"
arrangement of clauses in ascending order of forcefulness
the highest point of anything conceived of as growing or developing or unfolding; "the climax of the artist's career"; "in the flood tide of his success"