1. dad
2. dada, daddy, papa, pappa, pater, pop, father, male parent, begetter, protactinium
3. protoactinium, Pa, atomic number 91, metallic element, metal, pascal
4. Pa, pressure unit, Pennsylvania
5. Keystone State, PA, American state, public address system
5. P.A. system, PA system, P.A., PA, communication system