(UK, military, nautical, obsolete) Initialism of His/Her Britannic Majesty's Ship, replaced by HMS (His/Her Majesty's Ship).

(Internet) Initialism of how 'bout you?.

Initialism of human biodiversity.

(Internet slang, email, text messaging) Abbreviation of happy birthday.

(television, computing) Abbreviation of horizontal blanking.

(retail) health and beauty care / (veterinary medicine) hit by car / (organic chemistry) Abbreviation of hexabenzocoronene.

(organic chemistry) Abbreviation of hexabromocyclododecane. / Abbreviation of 1,2,5,6,9,10-hexabromocyclododecane.

Initialism of hydrobromofluorocarbon.

(US, education) Initialism of historically black college or university.

Alternative form of h bar