Predominant means most common, most powerful, or most noticeable among other things. When something is predominant, it stands out as the main or leading element in a group.

In a forest where oak trees are predominant, you'll see more oaks than maples, pines, or birches. When scientists study which animals are predominant in an ecosystem, they're identifying which species are most numerous or influential. If blue is the predominant color in a painting, that's the color that catches your eye first and appears most often.

The word often describes what has the most influence or control. In a classroom discussion, the predominant opinion is the view most students share. A predominant emotion is the feeling that's strongest at a particular moment: after winning a championship, joy might be the predominant feeling among team members, even if they also feel tired or relieved.

Notice that predominant doesn't mean “only.” Other things still exist alongside what's predominant. In a school where soccer is the predominant sport, students still play basketball, run track, and swim. The predominant thing is simply the one that appears most often, stands out the most, or has the greatest effect.