instrument (n.) 3
organ, faculty, functioning part
Cor I.i.99 [Menenius to Citizens, of the body parts other than the belly] th'other instruments / Did see and hear, devise, instruct
JC II.i.66 [Brutus alone] The genius and the mortal instruments / Are then in council
Oth I.iii.267 [Othello to all] light-winged toys / Of feathered Cupid seel with wanton dullness / My speculative and officed instruments [Q; F Instrument]