Proportionate means sized or scaled appropriately in relation to something else. When things are proportionate, they match or correspond properly, like how a dollhouse has tiny furniture proportionate to its tiny rooms, or how a recipe calls for ingredients in proportionate amounts: more flour than salt, more sugar than vanilla.

In math and science, proportionate relationships follow consistent ratios. If you're making lemonade and need two lemons for every cup of water, those ingredients are proportionate. Double the water, and you need to double the lemons to keep things proportionate.

The word often appears in discussions of fairness. A proportionate punishment fits the seriousness of what someone did: a small consequence for a minor mistake, a serious consequence for a major violation. If a teacher gave you detention for being two minutes late but gave the same detention to someone who skipped class entirely, those punishments wouldn't be proportionate to the offenses.

You might also hear about proportionate representation in government, where different groups get influence proportionate to their numbers. Artists think about proportionate features when drawing people, since a head that's too large or arms that are too short for the body can look wrong. Things feel right when they're proportionate.