My favorite word is crap.
It's a noun, a verb, and an adjective all in one. It is a cover all for anything dumb you do. You just say "oh crap" and it's magically a little better. If you get injured, you yell "crap" and you feel a little better, plus it sounds cooler than "ouch." It's a bit edgier than poop or doo doo so young children can't say it, but it's not so edgy you can't say it around young children.
And despite it's connotation with dirty things, we all owe it a debt of gratitude, as it has helped clean up society immensely. The entomology of the word crap places it at around the year 1846. There was a genius among plumbers who may have helped spur it's widespread adoption as a word.
Thomas Crapper. He didn't invent the toilet, but he helped foster it's adoption, and he invented the ball cock (that thing that stops filling the tank when it's full). Although I prefer a Fluidmaster style cut off, the ball cock is still in use today. In additon to flush toilets, Crapper's company also manufactured a line of quality bath fixtures such as faucets.
And, to complete the trifecta, not only is the word crap a useful catch all, and not only did a gentleman with the last name Crapper help clean up the world one bathroom at a time, the original inventor of the toilet was named Sir John Harrington.
You can't make this stuff up people.