Un-
Unhappy
Not happy
Incomplete
Not complete
Dishonest
Not honest
Prekindergarten
Before kindergarten
Posttest
Unlucky
Not lucky
Incorrect
Not correct
Disrespect
Not respect / without respect
Prepaid
Paid before
Post-war
Unkind
Not kind
Inappropriate
Not appropriate
Disagree
Not agree
Pre-write
Write before
Postseason
After the season
Unequal
Not equal
Invisible
Not visible (visible = can be seen)
Dislike
Not like
Preview
View before (view = see)
Postmortem
After mortem (mortem = death)
Unreal
Not real
Inactive
Not active
Discontinue
Not continue
Premade
Made before
Postscript (PS)
After script (script = writing)