Meaning

noun a thin coagulable fluid (similar to plasma but) containing white blood cells (lymphocytes) and chyle; is conveyed to the blood stream by lymphatic vessels

originBorrowing from French lymphe and/or Latin lympha (“clear water”), from Ancient Greek νῠ́μφη (nŭ́mphē, “bride; spring water”). Doublet of nymph.

Etymology from Wiktionary, CC BY-SA 3.0