The opposite of keeping something at arm's length is to embrace it. When we embrace something, we hold it close and cherish it. In the case of relationships, embracing means showing warmth and affection to the other person, while keeping them at arm's length implies detachment and distance. Similarly, when it comes to opportunities, embracing them means taking advantage of them and maximizing their potential, while keeping them at arm's length implies indifference and reluctance. In summary, embracing is the antonym of keeping at arm's length, and it involves actively engaging with the world and the people around us.