moderate
Not too much or too little; in the middle and reasonable.
Moderate describes something that's neither too much nor too little, but somewhere sensibly in the middle. A moderate speed isn't crawling or racing; moderate temperatures aren't freezing or scorching. When a doctor tells someone to exercise in moderation, she means don't overdo it, but don't skip it entirely either.
The word can describe people's views or opinions. A moderate position on a debate topic isn't extreme in either direction. Someone with moderate political views might agree with some ideas from different sides rather than taking the most intense position available. Teachers appreciate moderate voices in classroom debates: students who listen carefully and consider multiple perspectives rather than arguing the most extreme point possible.
As a verb, to moderate means to make something less extreme or to keep something under control. You might moderate your excitement in a library, or a teacher might moderate a heated discussion between classmates. A discussion moderator helps keep a conversation fair and balanced, making sure everyone gets heard and no one dominates.
The key idea is balance and reasonableness. Moderate choices avoid extremes. If you're moderately hungry, you'll eat a reasonable amount rather than stuffing yourself or barely nibbling. Moderation often reflects good judgment about what's appropriate for the situation.