Excerpt
              In corpus linguistics, a hapax
					legomenon (/ˈhæpəks lɨˈɡɒmɨnɒn/ also /ˈhæpæks/ or /ˈheɪpæks/;[1][2] pl. hapax legomena;
					sometimes abbreviated to hapax, pl. hapaxes) is a word that occurs only once within a
					context, either in the written record of an entire language, in the works of an author, or
					in a single text. The term is sometimes incorrectly used to describe a word that occurs in
					just one of an author's works, even though it occurs more than once in that work. Hapax
					legomenon is a transliteration of Greek ἅπαξ λεγόμενον, meaning "(something) said (only)
					once".[3]