A lot vs. Alot: 9 Grammatical Pitfalls
"of or near the kidneys," 1866, Modern Latin, from ad- + renalis "of the kidneys," from Latin renes "kidneys." Adrenal gland is from 1875.
adrenal ad·re·nal (ə-drē'nəl)adj.
At, near, or on the kidneys.
Of or relating to the adrenal glands or their secretions.