from the animated series "Home Movies", season four, episode called "Honkey Magoo"; Jason wants to call the lost dog "Smatchmo the trumpeteer"; alluding to "Satchmo" aka Louis Armstrong, a famous Jazz trumpeter.
authentic, raw, real, hardcore, manly; as opposed to wussified, metrosexual, fake
Usually used in connection with American Football, "to play smashmouth football"; allegedly coined by Chicago Bears coach Mike Ditka.
Also the name of two US-American bands.
"Oo-er, I'm afraid I've strained my ankle and need to be rushed to the hospital!"
"Forget it! We're playing smashmouth Rayman Raving Rabbids here!"