in physiology, "colorless fluid found in animal bodies," 1725, from French lymphe (16c.), from Latin lympha "water, clear water, a goddess of water," variant of lumpæ "waters," altered by influence of Greek nymphē "goddess of a spring, nymph."
The same word was used earlier in English in the classical sense "pure water, water" (1620s) and with reference to colorless fluids in plants (1670s). Also see lymphatic. Lymph node is attested by 1874.
word-forming element meaning "feeling, suffering, emotion; disorder, disease," from Latin -pathia, from Greek -patheia "act of suffering, feeling" (from PIE root *kwent(h)- "to suffer"). Meaning "system of treatment of disease, method, cure, curative treatment" is abstracted from homeopathy (q.v.).
<a href="https://www.etymonline.com/word/lymphadenopathy">Etymology of lymphadenopathy by etymonline</a>
Harper, D. (n.d.). Etymology of lymphadenopathy. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/lymphadenopathy