intentional
Done on purpose, with thought, not by accident.
Intentional means done on purpose, deliberately rather than by accident. When you do something intentional, you mean to do it: you've thought about it and chosen to act that way.
If you accidentally knock over your sister's tower of blocks while walking by, that's not intentional. But if you knock it over because you're annoyed with her, that's intentional. The difference matters: people respond very differently to accidents versus intentional actions.
The word shows up in many contexts. A teacher might ask for your intentional participation in class discussion, meaning she wants you to actively choose to contribute, not just speak up randomly. An artist makes intentional choices about colors and composition. A coach creates an intentional training plan rather than just having players run around without a plan.
Something intentional involves conscious thought and purpose. When someone is intentional about their friendships, they make deliberate efforts to stay connected. When someone is intentional about their studying, they focus with a plan rather than just flipping through a textbook hoping something sticks.
The opposite is unintentional, meaning accidental or done without meaning to.