Accountable means being responsible for your actions and willing to explain or accept the consequences of what you do. When you're held accountable for something, you can't just shrug and walk away: you need to own what happened and deal with it honestly.

If you promise to feed your neighbor's cat while she's on vacation, you're accountable for making sure that cat gets fed every day. If you borrow your friend's bike and it gets damaged, you're accountable for fixing it or replacing it. Being accountable means others can count on you to follow through on your commitments and to make things right when something goes wrong.

When you're accountable to someone, you owe them an honest explanation of what you did and why.

Teachers hold students accountable for completing homework. Referees hold players accountable for following the rules. Parents hold children accountable for doing their chores. In each case, being accountable means you can't just do whatever you want without consequences.