a escondidillas

== Spanish == === Pronunciation === Syllabification: a es‧con‧di‧di‧llas === Adverb === a escondidillas (idiomatic) behind someone's back; on the hush-hush === Further reading === “a escondidillas”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025