(technical diving, saturation diving, underwater diving) An electronic device that lowers the pitch of speech, to compensate for the high-pitched speech of someone breathing in a helium atmosphere breathing mix (ie. heliox, heliair, ...), so as to be understandable to other people.

A census-designated place in San Diego County, California, United States.

simple past tense and past participle of hold water

(slang, euphemistic) A tranquilizer taken to reduce anxiety; meprobamate, diazepam.

A species of plover, Charadrius sanctaehelenae, endemic to the remote island of Saint Helena in the Atlantic Ocean.

plural of St Helena plover

A leather head covering with earflaps used by early aviators.

A balaclava (type of headgear).

A mining helmet, a hard hat worn by miners that usually carries a light on the front. / Eggcorn of pith helmet.

(US, conspiracy theories) A secret covert government helicopter of the deep state, used for clandestine missions, such as UFO cover-ups or capturing political prisoners.