How about Fishing? Build a Fishing Dock in a place with water. Settlers assigned to it will catch fish for food.
Hunting? Similar, create a Hunter's Rack. A settler will go out an hunt, bringing in animal parts. However, that settler is not available for defense.
Become a Minuteman. Minuteman Armory, settlers assigned train as minutemen, get the gear. Will respond to flares.
Lookout. Watchtower, assigning a settler gives more advanced warning of raids, strengthens the defense.
Repairman. Workshed, assigning a settler automatically repairs damaged items and increases the efficiency of generators, purifiers, beacons, etc.