Odd !
The opposite of an even number is an odd number.
The opposite of odd is even. If you divide a even or odd number with odd, you will still get a fraction, or a romander.
It's opposite is a negative. :P
working even harder
even number
The opposite word of space is crowded. Or even cramped would work.
The opposite of elusive (evasive) could be confronting or even enticing. The opposite of elusive (difficult to perceive) would be obvious, clear, or simple.
The answer depends on where opposite! Even if you could spell correctly, the answer would depend on whether you meant the additive opposite or the multiplicative opposite.
The opposite of friendly is "unfriendly" but you can also use aloof, stand-offish, or even unwelcoming.
The opposite of somewhere (unspecified location) could be nowhere, or it could be here (opposite of (somewhere else or there), or even there. (a specified location).
A line through the vertex and the side opposite - nothing more. There need not even be a side opposite - as is the case with a square!
If you have to be opposite on opposite day, that makes it a day, and then there was no opposite day. But that can't be true since you HAVE to be opposite, which means that you have to be normal even though there is an opposite day because you are supposed to be opposite on opposite day, which means that you act normal as if it was a normal day, because that is the opposite of opposite day. (This is a classic "liar's paradox". Since there is already an opposite day, you should have a normal day because that is the opposite of an opposite day. But then it is not an opposite day.)