late 14c., "boundary, frontier," from O.Fr. limite "a boundary," from L. limitem (nom. limes) "a boundary, embankment between fields, border," related to limen "threshold." Colloquial sense of "the very extreme, the greatest degree imaginable" is from 1904. The verb is late 14c., from O.Fr. limiter, from L. limitare "to bound, limit, fix," from limes.