Latin, translation: "Thus always to tyrants", purportedly (but unlikely) uttered by Brutus at the assassination of Julius Caesar. The phrase is meant to signify that tyrants will always be overthrown and removed from power.
The other person who defined this just got it flat out wrong. Didn't think people could be that stupid.
mutation from the Latin meaning "always a dog", always being a dog, always base and self-gratifying, always begging handout, freebees, sex, gratuities. Always "dogging it".
When Zeb related to ladies and friends in his base self-serving way he was "Semper Fido" - always doglike.
Adaptation of the Marine Corps motto: Semper Fi (Latin for Always Faithful). Used to describe the general Marine attitude (i.e always be flexible with plans cause something will change that will fuck up your night) towards the constant changes that are rampant in every Marine unit.
Marine 1: Hey man, go easy at the bar tonight, just found out we have a CFT at 04
Marine 2: Oh well, semper gumby
Eternal and Everlasting; also coincidentally the name of the latestBring Me The Horizon album. The title comes from a line in the song, "THIS IS SEMPITERNAL, WILL WE EVER SEE THE END? THIS IS SEMPITERNAL, OVER AND OVER AGAIN AND AGAIN."
Also a common joke that it is really "sandpit turtle".....it isn't
boy: "Wow, that new BMTH album is really good!"
friend: "Yeah, I love sempiternal!"
teacher: "They saw that knowledge is eternal."
other teacher: "indeed, it is sempiternal!"