guard dog (NOTE: The British term is Alsa-tian.)

One who cares for and guides a group of people, as a minister or teacher, A man who herds, tends, and guards sheep in pasture; a pastor, A person who tends sheep, verb_ To watch over; to guide, watch over like a shepherd, as a teacher of her pupils, tend as a shepherd, as of sheep or goats, transitive verb_ Poetic To tend as a shepherd; to guard, herd, lead, or drive, as a shepherd, To direct or instruct in a certain manner, To guide or lead on a course

A Christian minister or priest having spiritual charge over a congregation or other group, One who has the care of a flock or herd; a herdsman; especially, a shepherd, A guardian; a keeper; specifically (Eccl.), a minister having the charge of a church and parish, verb_ Christianity To serve a congregation as pastor