A posimistic person is someone who has a very positive, affirmative, optimistic, favorable outlook on life.
It's actually a combination of the words postive and optimistic, hence " posimistic", "posimist " & " posimism ".
The opposite would of-course be "negamistic" , "negamist ", " negamism ", which is a combination of the words " negative " and " pessimistic " !
"Charlie is always posimistic, expecting the best in this best of all possible worlds, but sooner rather than later he must come to the realization that he cannot have his cake and eat it too !"
being positive and optimistic (as seen on bigbrother)
bobbie; my new job sux, i recon ima throw in the towl...
harriet; no cum'on be posimistic ...give it a chance!
bridget;i want my clothes back!
travis; stay posimistic bridge!