A narrow hole drilled or punched into a surface, to facilitate the insertion of a wider screw, nail, drill bit, or other boring tool.

(slang) A clergyman, especially a military chaplain or padre.

A proof of concept; an initial prototype.

A small-scale chemical engineering facility designed to research the full-scale production of a product.

Either of two species of whale in the genus Globicephala, dark grey in colour.

Alternative spelling of pilot hole

A pilot available for hire to fly, typically over short routes in light aircraft

(chiefly Canada, Australia, New Guinea) A pilot who flies small aircraft to and from remote locations, over expanses of relatively unpopulated territory.

(film, television) A film, miniseries, or episode that serves as a proof of concept for a new full television series, but may be broadcast on its own even if the full series does not come to fruition.

(US, military, aviation) An aircraft that may be manned or unmanned, able to function in either mode without modification.