English: 1. habitational name from a place in Hertfordshire, recorded in 1262 as Croyroys, from Old French croiz ‘cross’ (Latin crux, genitive crucis) + the female personal name Royse (see Rose 2). Ekwall mentions forms from only twenty years later in which the place name first more or less assumes its modern form. It is not clear, however, whether this is to be interpreted as ‘Royse's stone’ (with the second element Middle English stōn, from Old English stān) or ‘settlement at (Croiz) Royse’ (with the second element Middle English toun, from Old English tūn). 2. habitational name from a place in West Yorkshire, so called from the genitive case of the Old English byname Hrōr, meaning ‘vigorous’ (or its Old Norse cognate Róarr) + Old English tūn ‘enclosure’, ‘settlement’. 3. Americanized form of one or more like-sounding Jewish surnames.