exhibitionist:
(plural: ‘exhibitionists‘; pronunciation: the letters ‘hi’ are silent; the word opposite word in meaning: ‘voyeur’, ‘peeper‘ or ‘peeping tom’; for the right pronunciation of exhibitionist, please click here)

an exhibitionist acting silly to draw attention from the passers-by
a person who wants others to look at and admire him/her, and always behaves in such a way that he/she attracts the attention of others;
a show-off;
a peacock;
a person who has the strong desire/habit of showing his/her sex parts in public in order to get attention (a mental sexual disorder);
a ‘flasher’,
Jimmy, the mildest of our gang of friends, has been acting strange these days, and we suspect that he’s becoming an exhibitionist.
Though most exhibitionists are harmless, there may be some, mostly middle-aged men, exhibitionists who tend to harm their onlookers.
According to the law of the land, exhibitionism is a crime and exhibitionists of all kinds are criminals and are subjected to legal punishment.
It’s interesting to note that only male exhibitionists are reported to the law and female exhibitionists, though despised openly by the men folk, are encouraged secretly!

an exhibitor with his exhibit (his painting) at an art exhibition
However, there are occasions where we see ‘exhibitionist’ being used for ‘exhibitor’ in a positive connotation/sense. For an article that explains the difference between an ‘exhibitionist’ and an ‘exhibitor’, please click here.
