*7.
adj. 1 good or useful: Keeping a pet can have a ~ effect on children. We need to make some ~ changes to our lives. 2 thinking or talking about the good parts of a situation: It's important to stay ~. The teacher was very ~ about my work. opposite: negative 3 showing that something has happened or has been found: a ~ pregnancy test He tested ~ for drugs. 4 completely certain SAME MEANING sure: Are you ~ that you closed the door?