(aviation) In air combat training, the minimum allowed altitude below which the aircraft is considered destroyed by ground impact.

(Internet) A paywall that hides all content from unregistered or nonpaying users.

plural of hard paywall

A jadeite mineral gemstone. / A gem made of such material.

plural of hard cheese

hardened against radiation damage

plural of hard currency

(finance) Any globally traded currency that serves as a reliable and stable store of value.

Alternative spelling of hard hit

Alternative form of hard hit