hollow: [12] Modern English hole comes from an Old English adjective meaning ‘hollow’, and by a coincidental swap hollow originated in an Old English word for ‘hole’ (the two are probably ultimately related). Old English holh meant ‘hollow place’, ‘hole’, or ‘cave’, and presumably came from the same source as produced Old English hol ‘hollow’. In the early Middle English period it began to be used as an adjective, its inflected form holge having become holwe, later holew or hollow. => cauliflower[hollow etymology, hollow origin, 英语词源]