testa di ponte — meaning in English

English meaning

airhead noun An informal, mildly insulting term for a foolish or unintelligent person.
beachhead noun A secured area on an enemy shoreline used to bring in more troops and supplies during an invasion.
bridgehead noun The area of land next to one end of a bridge.
liaison noun A person who acts as a link between two groups, passing information back and forth.

testa di ponte is used for these senses in English:

airhead (military) An area of hostile territory that has been seized for use as an airbase to ensure the further safe landing of troops and materiel.
beachhead (military) An area of hostile territory (especially on a beach) that, when captured, serves for the continuous landing (or movement into position) of further troops and material
bridgehead (military) An area of ground on the enemy's side of a river or other obstacle, especially one that needs to be taken and defended in order to secure an advance.

noun A secured area on an enemy shoreline used to bring in more troops and supplies during an invasion.
noun An initial foothold or early success that makes further progress possible.