quid pro quo/ˌkwid proh ʹkwoh/ noun (pl quid pro quos)

• horn-mad
• horn of plenty
• hornpipe
• horn-rims
• hornswoggle
• hornworm
• hornwort
• horny
• horologe
• horology
• horoscope
• horrendous
• horrible
• horrid
• horrific
• horrify
• horripilation
• horror
• horror-stricken
• horror-struck
• horror vacui
• hors concours
• hors de combat
• hors d'oeuvre
• horse