User:SilentPager

Hallo I want to ask a question. If I have a new word I want do define... Can I just do that and create an entry on Wikipedia? I want to add the word Astrosexual to Wikipedia. Now this is a new word I can not find on here. I do not know if I am allowed to do that because it would be all based on my definition. If I can not do that let me know. I will just wait for an admin or anyone from Wikipedia to come back to me. Thank you