serving or acting as an instrument or means; useful; helpful.

performed on or written for a musical instrument or instruments

instrumental music.

of or pertaining to an instrument or tool.

Grammar .

(in certain inflected languages, as Old English and Russian) noting or pertaining to a case having as its distinctive function the indication of means or agency, as Old English beseah bl?the andweitan looked with a happy countenance.

noting the affix or other element characteristic of this case, or a word containing such an element.

similar to such a case form in function or meaning, as the Latin instrumental ablative, gladi?, by means of a sword.

(in case grammar) pertaining to the semantic role of a noun phrase that indicates the inanimate, nonvolitional, immediate cause of the action expressed by a verb, as the rock in The rock broke the window or in I broke the window with the rock.

Grammar .

the instrumental case.

a word in the instrumental case.

a construction of similar meaning.

a musical composition played by an instrument or a group of instruments. Compare vocal ( def. 8 ) .

adjective

unhelpful , useless

adjective

active , auxiliary , conducive , contributory , helpful , helping , involved , of help , of service , partly responsible , serviceable , subsidiary , useful , assisting , crucial , essential , influential , vital