una corda

UK: /ˈuːnə ˈkɔːdə/

US: (o̅o̅′nə kôr′də; It. o̅o̅′nä kôr′dä)

WordReference Random House Unabridged Dictionary of American English © 2025

u•na cor•da  (o̅o̅′nə kôr′də; It. o̅o̅′nä kôr′dä), 

1. Foreign Terms, Music and Dance with the soft pedal depressed (a musical direction in piano playing).

• Italian: literally, one string, since depressing the soft pedal shifts the hammers so as to strike only two (origin, originally one) of the strings provided for each note
• 1840–50

Collins Concise English Dictionary © HarperCollins Publishers::

una corda / ˈuːnə ˈkɔːdə/ adjective , adverb

1. (of the piano) to be played with the soft pedal depressed

Etymology: Italian, literally: one string; the pedal moves the mechanism so that only one string of the three tuned to each note is struck by the hammer