Eighth (slang) Type: noun, slang Pronunciation: /ate-th/ Plural: Eighth’s What does Eighth mean? An 1/8 ounce of marijuana (3.5 grams). Similar to Eight: Pound, QP, Half, Quarter, Zip Example sentence: “Yo, can you hear me? i wanna buy an eighth.” Eighth in songs: “You smoke faster than me with a eighth” – ScHoolboy Q, BET […]