What is "absciss"

Absciss \Ab"sciss\, n.; pl. Abscisses. See Abscissa.

Etymology 1 n. (alternate form of abscissa English)(First attested in the late 17^th century.)(R:SOED5: page=8) Etymology 2

vb. 1 (context transitive English) To cut off by abscission. (First attested in the mid 19^th century.) 2 (context intransitive English) To separate (as a leaf from a twig) by abscission. (First attested in the mid 19^th century.)