Definition
To act 'territorially' means to behave in a way that defends or marks a specific area as one's own. It implies a sense of ownership and a willingness to protect that space from intruders. This can involve physical displays of dominance, marking boundaries, or aggressively defending resources within the territory. Think of it as 'staking your claim'. It suggests a primal instinct to control and protect one's domain. Even pets, like cats, act territorially.