extra hours or extended hours
It means more than normal, or more than enough.
Gravy is the tasty sauce you pour over meat to make it taste better and be juicy. You don't need it for a meal, but it's nice to have. The figurative meaning is anything not needed, but an extra bonus on top.
It means to have an advantage over someone - or it might mean that you invited Dave Evans from U2 to your house.
reccuring, happening again and again
It means getting three extra lives after GAME OVER
Extra baggage normally means extra weight or fat
it means extra extra large
It means extra extra large.
an extra-terrestrial, an alien
i think there shouldn't because i mean there over there weight limit and they need extra insurance on them just in case of emergency health and stuff like that.
Extra extra small or large
Extra over could be the additional sum of money allowed for items of work, that may have to be changed during construction.
Extra fast.
Surplus is extra.
"Going the Extra Mile" means that taking whatever you're taking one step further. For example, during school and if there is extra credt offered, "going the extra mile," would mean doing the extra credit. Even if it optional.
extra heart.