1. A support usually of stone or brick; supports the wall of a building
   "The Gothic cathedral's buttressing allowed for higher, thinner walls and larger windows";
   - buttress

1. Make stronger or defensible
   "buttress your thesis"
    
2. Reinforce with a buttress
   "Buttress the church"

Type of: beef up [informal], fortify, reenforce, reinforce, strengthen, support

Encyclopedia: Buttress, William