'Patio' came from Spanish, possibly pre-Roman Iberian — its ultimate origin is unknown despite global use.
A paved outdoor area adjoining a house.
From Spanish patio (an inner courtyard, an open court within or adjacent to a building), of uncertain ultimate origin. The most favoured etymology derives it from Vulgar Latin *patitum or *patium, from Latin patēre (to lie open, to be exposed, to spread out), from Proto-Indo-European *peth₂- (to spread out, to fly, to stretch). Latin patēre gives patent (lying open, then a document publicly open), patulous (spreading, open), and possibly pace (a step — the space one spreads out). An alternative etymology connects Spanish patio to the Mozarabic (Iberian Arabic
'Patio' entered English from Spanish in the nineteenth century, reflecting the influence of Spanish-speaking cultures on American English, particularly in the Southwest. In traditional Spanish architecture, the 'patio' is not a backyard addition but the central organizing feature of the house — rooms arranged around an open courtyard, providing light, air, and a private outdoor living space within the home.