Simple categories matching rugged:

• vehicle,
• surface,
• use,
• system,
• material,
• form,
• equipment,
• program,
• activity,
• terrain,
• situation,

Members with property rugged:

• pavement,
• tile,
• canyon_wall,
• slate,
• engine,
• desert,
• cobblestone,
• pond_monitoring,
• expedition,
• fire,
• truck,
• jeep,
• grassland,
• aluminum,
• swimming,
• staircase,
• sport,
• khakis,
• aluminum_alloy,
• fallen_tree,
• structure,
• truck_inspection,
• metal,
• carbon_fiber,
• camping_gear,
• corner,
• jean,
• hill,
• snowboarding,
• cotton,
• training,
• wood,
• sport_program,
• nail,
• linen,
• nylon,
• youth_sport,
• iron,
• game,
• leather,
• fin,
• stone,
• camping,
• field_use,
• outdoor_pursuit,
• unfinished_wood,
• corduroys,
• metal_rack,
• steel,
• canvas,
• mobile_computer,
• pvc,
• oak,
• bronze,
• irregular_surface,
• car_wash,
• asphalt,
• construction_site,