a person who spoils other people's enjoyment

Example: I hope you have not asked Mark to come to the party. He is a spoilsport and we will not have a good time if he is there.

abuse

(n)

insulting and offensive language

Example: The crowd shouted abuse at the Prime Minister as he got into his car.

perspex

(n)

a tough transparent plastic that looks just like glass

Example: The table top is perspex. It is much safer than glass because it will not shatter if you drop something onto it.

incredible

(adj)

unbelievable; the opposite of credible

Example: It is incredible that he is saying these things to his boss.

illusion

(n)

something unreal or imaginary

Example: I think that David Blaine's stunt in the perspex box is a brilliant illusion. I don't think that he was there at all.