Here's a hard-working little word:
A pug's a dog:
Hogarth the painter with his pug Trump in 1745.
Pug dogs usually have wrinklier noses than that nowadays. They've been bred in China, where they were reckoned to look like lions, since before 400 BC. In fact they were thought to look so much like lions that statues of pugs were used to guard temples.
This other small snub-nosed thing is a pug, too:
"Nora No.5", a typical 'Pug' built in 1912
A pug can also be a moth (in fact there are lots of species of pug moth, many of which often look so much like each other that they seriously annoy moth recorders):
That's a Common Pug, Eupithecia vulgata.
Pug can be clay and water mushed up together to make a...well, a mush, which can be used to fill up holes.
Pug is also a slang name for a boxer (not the dog, this time, but the fighter).
Pug can be sawdust, mortar or similar stuff put between a wooden floor and a ceiling to cut down noise (this is sometimes rather charmingly called pugging). A Pug Impression Pad is an area of finely raked earth used to collect evidence of animal life from footprints, especially tigers.
And if all those things are nowhere to be found then there's always the lovely New Zealand word puggy (there's puggier and puggiest, too,) which means sticky and claylike. All the footpaths are pretty puggy round here at the moment.
Easier still, a pug nose turns up at the end; and, lastly, a pug can be a tangle in the hair.
There we are. Pugs? We're surrounded by them!
Spot the frippet: pug. Pug meaning boxer is short for pugilist, from the Latin word pugil, a boxer, which is related to pugnus, a fist. The train may be called after the dog, or perhaps from the dialect word pug which means monkey. Sadly, the origins of the other meanings have been lost in the midsts of time.