pluscuamperfecto.

(a loanword from Spanish)

Headword: 
pluscuamperfecto.
Principal English Translation: 

pluperfect (a preterit form and a term used in music)
(a loanword from Latin and Spanish)

Orthographic Variants: 
plusquanynperfecto, pluscuaperfecto, prucuaynperfecto
Attestations from sources in Spanish: 

yzcatliqui tono: pluscuaperfecto quituznequi quipanui: yn nahuatili yn maestro = pluscuamperfecto significa que escapa a la regla del maestro;
prucuaynperfecto = pluscuamperfecto;
yc tecmos yc necis plusquanynperfecto = para descender y mostrarse pluscuamperfecto (seventeenth-century Guatemala)
Fernando Horcasitas y Alfred Lemmon, "El Tratado de Santa Eulalia: un manuscrito musical náhuatl," Tlalocan 12 (1997), 96–97.