FOOTHOLD
beachhead, foothold
(noun) 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”
foothold, footing
(noun) a place providing support for the foot in standing or climbing
bridgehead, foothold
(noun) 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”
Source: WordNet® 3.1
Etymology
Noun
foothold (plural footholds)
(climbing) A solid grip with the feet.
(by extension) A secure position from which it is difficult to be dislodged.
(military) Airhead, beachhead, bridgehead, lodgement.
Source: Wiktionary
Foot"hold`, n.
Definition: A holding with the feet; firm L'Estrange.
Source: Webster’s Unabridged Dictionary 1913 Edition