"Misterioso" is an Italian term that translates to "mysterious" or "mysteriously" in English, conveying the meanings of "enigma" or "secrecy".

In music, "misterioso" is an instruction used to guide performers to play with a mysterious or enigmatic quality, evoking a sense of intrigue and uncertainty.

In other words, when interpreting "misterioso", performers should aim to create a musical performance that conveys a sense of mystery and ambiguity, allowing the audience to experience a musical ambiance that reflects the enigmatic and secretive nature of the piece being played.

Example of Misterioso

Esa-Pekka Salonen | Mahler's Third Symphony | IV. Sehr langsam—Misterioso (Philharmonia Orchestra)