1. To remain in one's company indefinitely or for an extended period of time, especially to provide them with care. His parents didn't leave his side for the whole time he was in the hospital. Whenever our kids get sick, they never let us leave their side.

2. To remain married to and supportive of one, especially during and/or after some trouble or hardship. He did not leave my side, even though I'd squandered our life savings on a get-rich-quick scheme. The senator's wife today reiterated that she wouldn't leave her husband's side amid the scandal.