MEANING: noun:
1. An accessory, embellishment, or byproduct of a main work.
2. Subsidiary work undertaken in addition to one’s main employment.

ETYMOLOGY: From Greek parergon, from para- (beside) + ergon (work). Ultimately from the Indo-European root werg- (to do), which also gave us ergonomic, work, energy, metallurgy, surgery, wright, erg, georgic, and hypergolic. Earliest documented use: 1601.

SPARERGON - a many-sided geometric figure with fewer sides than another one you were thinking of

PAPERGON - Hey! Somebody took my New York Times !

PARERGO - a golf score you have to achieve in order to participate in elite tournaments
Example: "He didn't make PARERGO he's not in the final rounds of the US Open."