pĕr-ăcerbus

a, um, adj.
I. very harsh to the taste.
I. Lit.: uva peracerba gustatu, Cic. Sen. 15, 53.—
II. Trop., very painful: mihi peracerbum fuit, quod, etc., Plin. Ep. 6, 5, 6.
Lewis & Short
A Latin Dictionary, 1879
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