semibasement

[ sem-ee-beys-muh nt, sem-ahy-, sem-ee-beys-, sem-ahy- ]
/ ˌsɛm iˈbeɪs mənt, ˌsɛm aɪ-, ˈsɛm iˌbeɪs-, ˈsɛm aɪ- /

noun

a basement partly above ground, as in a house built on a slope.

Origin of semibasement

First recorded in 1870–75; semi- + basement