The story
- Old French · derived fromplaintif“complaining”; as a noun, “one who complains, a plaintiff”
- Middle English · inherited fromplaintif
- English todayplaintiff
From Middle English plaintif, from Anglo-Norman, from Old French plaintif (“complaining”; as a noun, “one who complains, a plaintiff”) from the verb plaindre. Doublet of plaintive.
Etymology from Wiktionary, CC BY-SA 4.0.