1749, "of or pertaining to segments;" 1787, "having the form of a segment;" see segment (n.) + -al (1). Segmentary in the same sense is attested from 1831. Related: Segmentally.
Entries linking to segmental
segment n.
1560s, in geometry, "plane figure contained by a right angle and a part of a circumference of a circle," from Latin segmentum "a strip or piece cut off, a cutting, strips of colored cloth," from secare "to cut" (from PIE root *sek- "to cut"), with euphonious alteration of -c- to -g- before -m-.
Latin segmentum was used in Medieval Latin as a geometry term, translating Greek tmema. The meaning "segmental portion of anything circular" is from 1640s; the general sense of "a division, section, part cut off or marked as separate from others" is from 1762.
-al 1
suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).