As I start a semester, I thought this word was apropos. Also, I know a lot about some languages, but can’t necessarily speak them well.
pantoglottism, n. ‘ Knowledge of all languages.’
Etymology: < panto- comb. form + ancient Greek γλῶττα (see -glot comb. form) + -ism suffix. Compare later pantoglot n. and adj. and slightly later polyglottism n.
Obs. rare. Knowledge of all languages.1848 J. R. Lowell Biglow Papers 1st Ser. ii. 28 This would argue for the pantoglottism of these celestial intelligences.