instrumental

adjective

• 1serving as an instrument or means in pursuing an aim or policy:the society was instrumental in bringing about legislation
• relating to something’s function as an instrument or means to an end:a very instrumental view of education and how it relates to their needs

• 2(of music) performed on instruments, not sung:a largely instrumental piece
• relating to musical instruments:brilliance of instrumental color

• 3of or relating to an implement or measuring device:instrumental error instrumental delivery of a baby

• 4 Grammar denoting or relating to a case of nouns and pronouns (and words in grammatical agreement with them) indicating a means or instrument.

noun

• 1a piece of (usually nonclassical) music performed solely by instruments, with no vocals.

• 2 (the instrumental) Grammar the instrumental case.
• a noun in the instrumental case.