Meaning

noun a second-year undergraduate

adjective used of the second year in United States high school or college

originFrom earlier sophumer, from the obsolete sophom, sophum (“sophism or dialectical exercise”), from Ancient Greek σόφισμα (sóphisma). Likely influenced by Ancient Greek σοφός (sophós, “wise”) + μωρός (mōrós, “fool”). Compare oxymoron (literally “sharp-dull”), a similar contradiction.

Etymology from Wiktionary, CC BY-SA 3.0