curmudgeon
An ill-tempered person full of stubborn ideas or opinions, often an older man.
Near-synonyms: crank, grump; grumpy pants (often childish), sourpuss, grouch
A miser.
archaic
Where it comes from
Numerous folk etymologies exist for this word. An alternative spelling attested in 1600 is cornmudgin, in Holland's translation of Livy, rendering Latin frūmentārius (“corn-merchant”). This has been suggested as the original form of the word, but OED notes that curmudgeon is attested some years before this, concluding that cornmudgin was merely a nonce-word by Holland. The word is attested from the late 1500s in the forms curmudgeon and curmudgen, and during the 17th century in numerous spelling variants, including cormogeon, cormogion, cormoggian, cormudgeon, curmudgion, curmuggion, curmudgin, curr-mudgin, curre-megient.
Adapted from the Wiktionary entry curmudgeon (CC BY-SA 4.0).