"pertaining to the corpus callosum," 1864, from Latin callosus (see callous) + -al (1).
Entries linking to callosal
callous adj.
c. 1400, "hardened," in the physical sense, from Latin callosus "thick-skinned," from callus, callum "hard skin" (see callus). The figurative sense of "unfeeling, hardened in the mind" was in English by 1670s. Related: Callously; callousness.
-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)).