adjective 1.having the shape or appearance of an umbo; bosslike: an umbonal structure.
2.of, pertaining to, or near the umbo: the umbonal region.
Origin: 1850–55; <
Latin umbōn- (stem of
umbō; see
umbo) +
-al1 Related forms post·um·bo·nal, adjective
pre·um·bo·nal, adjective
sub·um·bo·nal, adjective