supposed to typify public lavatories: the lavatorial utility that was a feature of subway design. lav*a*to*ry n. (pl. -ries) a room or compartment with a toilet and washbasin; a bathroom. - a sink or washbasin in a bathroom. - BRIT. a flush toilet. late Middle English: from late Latin lavatorium 'place for washing', from Latin lavare 'to wash'. The word originally denoted something in which to wash, such as a bath or piscina, later (mid 17th cent.) a room with washing facilities; the current sense dates from the 19th cent. la*va tube n. a natural tunnel within a solidified lava flow, formerly occupied by