Answer: reinforce

AnswerCrossword Clue
REINFORCEAdd extra support to
REINFORCEStrengthen.
REINFORCEStrengthen
REINFORCEButtress
REINFORCEBring in more troops
reinforceto strengthen with new force, assistance, material, or support also REENFORCE, RENFORCE
reinforceto strengthen with support, troops, etc.