(n.) an ornate door knocker in the shape of a grotesque face or creature
You know that moment in A Christmas Carol where Scrooge’s doorknob transmogrifies into the face of his departed business partner, Jacob Marley? Here’s a nice word to tie in with that: a mascaron is an ornate door knocker, shaped like a grotesque face or creature.
(And, yes, as some of you clever, clever people pointed out on Twitter, that is the door knocker of the sanctuary of Durham Cathedral. 10 points to Gryffindor!)
That being said, this is just one meaning of the word here. More generally, a mascaron is a grotesque face used as any kind of decorative architectural feature. You’ll often find them atop gothic pillars, or decorating the ramparts of equally old towers, columns and similar structures. They’re different from gargoyles, because they have a purpose: gargoyles take their name from an Old French word for the throat, gargoule, because they channel rainwater out of their mouths and away from the brickwork of the building they cling to. Mascarons, though, are simply decorative.
The word mascaron is French too, but its origins can be traced back via Italian to Latin word masca—which is where the word mask comes from, as well as mascara and masquerade. The –on is a French addition too; Latin nouns sometimes had a suffix –o (or, in certain grammatical contexts, –onem) added to them to create agent nouns or nicknames. These words took an –one ending in Italian, which morphed into –on or –oon in French, and ultimately in English.
So in Latin, a balatro was a joke teller; we’ve ended up with balatron, an old word for a jester. A ponto was a flat-bottomed boat; we call it a pontoon. Draco is the Latin for ‘dragon’; we use the word dragon too, but this is also the origin of a dragoon. And Latin lacus, via a few different avenues, eventually gave us the word lagoon as well as lake.