n. & adj.
n. 1 one more than seventeen, or eight more than ten; the product of two units and nine units. 2 a symbol for this (18, xviii, XVIII). 3 a size etc. denoted by eighteen. 4 a set or team of eighteen individuals. 5 (18) Brit. (of films) classified as suitable for persons of 18 years and over.
adj. that amount to eighteen. eighteenth adj. & n.
[ OE ehtatene, eaht- ]