Fake Etymology III

Was the term "hot dog" invented when a cartoonist couldn't spell "dachshund"? Of course it wasn't.

Why was French Revolutionary hero Robespierre known as “the sea-green Incorruptible”?
He was said to be unable to be corrupted, or bought off (the Incorruptible part). He is supposed to have worn a sea-green cockade in his hat, hence the sea-green part.
He was as incorruptible as the sea was green.
Mme de Stael said he was pale, with green veins. Carlyle translated this to sea-green, “atrabiliar”, and went on about it.
Someone else at the time or nearer it said he had greenish spectacles.
Take your pick.

Cliché: from the sound of the printing press: clee shay clee shay clee shay. Or from the word for a block of standing type.

once in a blue moon: If there are two full moons in a month, the second is the “blue” moon.

gabardine: Invented by Alice Gabardine in 1888.

horchata: It’s a traditional drink made from nuts. The Free Dictionary says: Various folk etymologies exist – one legend links the origins of the name to James I of Aragon, who after being given the drink for the first time by a local in Alboraya, was said to have exclaimed "Això és or, xata!" ("That's gold, darling!")

loo for toilet: from the trade name Waterloo, which featured on iron cisterns

groat: "John o’Groats is called after Jan de Groot, who ran a ferry from there (to Orkney, Fair Isle and Shetland, probably). The fare was 4d. Hence groat, which is how you pronounce Groot." (Bill Bryson’s Notes from a Small Island)

kangaroo: the Australian aborigine for "What is that?"

boomerang: So-called because when early settlers asked the aborigines what the device was called, they answered "boomerang", meaning "it has no name".

light or heavy hearted: from the ancient Egyptians thinking that after death your heart was weighed against a feather

sleep tight!: Mattresses used to be secured on bed frames by ropes.When you pulled the ropes the mattress got firmer, hence the phrase “Goodnight, sleep tight” says @LadyKentmores (George Johnson) Or is it because the mattress rested on a network of ropes which needed tightening occasionally? (Lucy Worsley)

More here, and links to the rest.