Inside is the opposite word of outside
Inside is the opposite word of outside
Inside.
Endo (inside of)
opposite front side
garden?
Extremity, torso, inside, middle...
For opposite day, just wear what you normally do, but wear it either backwards or inside out. (of course you could do both!)  socks you must wear inside out.
The opposite of exterior is interior meaning inside
The opposite in location for a gravy or sauce could be a "filling" (inside, not outside).
It is the bend in your arm (on the inside, opposite from your elbow).
Yes, "inside out" refers to the inside being turned outwards, while "outside in" would mean the opposite, where the outside is being brought towards the inside.