The adjective tutelary describes something that is supervising or guarding something else, like the tutelary duties of a babysitter who makes sure the kids don't hurt themselves at the playground.
To correctly pronounce tutelary, say "TOO-tuh-leh-ree." Tutelary comes from the Latin word tutus, meaning "watch over." You see this root in words like tutor and tutorial, which also involve watching over, though in a more specific sense that applies primarily to instructing. Tutelary's suffix -ary means "having to do with." So something that is tutelary has to do with keeping watch, like the tutelary presence of a parent supervising a child, or even a tutelary god in an ancient society.