spare, adj. > A spare part ... is an interchangeable part that is kept in an inventory and used for the repair or replacement of failed units. [0] https://en.

spare, adj. > A spare part ... is an interchangeable part that is kept in an inventory and used for the repair or replacement of failed units. [0] https://en.wikipedia.org/wiki/Spare_part https://en.wikipedia.org/wiki/Spare_part > kept in reserve, as for possible use > being in excess of present need; free for other use [1] http://dictionary.reference.com/browse/spare?s=t http://dictionary.reference.com/browse/spare?s=t A replacement part made on demand is by definition not "spare". Let's not have this word go the way of "drone", please?