chiasma chiasm • chiasmal · · · Info · Definitions · Synonyms · Characters · · chiasma · · Text Latin · · Script 7 · · Length 3 · · Syllables Definitions · · · (noun) an intersection or crossing of two tracts in the form of the letter X. Synonyms: chiasm, decussation. · · Noun Definition 1 Synonyms · · · chiasm · · Synonym 1 decussation · · Synonym 2 Characters · · a latin small letter a U+0061 c latin small letter c U+0063 h latin small letter h U+0068 i latin small letter i U+0069 m latin small letter m U+006D s latin small letter s U+0073