A musical instrument borrowed or used as a backup for when a musician forgets or doesn't have his own. An apple cider instrument may typically be broken, in poor condition, and/or very old. A school with a music program may have apple cider instruments on hold for use by forgetful students.

Refers to the act in which the male reproductive organ enters the female reproductive tract as a result of copulation.

When a man or woman of age utilizes their instrument of choice a little more than necessary, it is referred to as "musical instrument intercourse". It can happen with every instrument, but it is most commonly practiced with any instrument that has removable parts (i.e. brass instruments).

A variant of the term 'Whatever floats your boat'.
'Whatever piddles your fiddle' = 'Whatever pisses your instrument'

A type of mint

When you sexually assault a musical instrument, because musical instruments cannot consent.