Strengthen Strengthen synonyms fortify strengthen and fortify harden strengthen and harden reinforce strengthen and reinforce intensify strengthen and intensify toughen strengthen and toughen brace strengthen and brace consolidate strengthen and consolidate heighten strengthen and heighten enhance strengthen and enhance increase strengthen and increase Full list of synonyms (2126) Strengthen antonyms weaken strengthen and weaken undermine strengthen and undermine reduce strengthen and reduce soften strengthen and soften lessen strengthen and lessen decrease strengthen and decrease destroy strengthen and destroy debilitate strengthen and debilitate sap strengthen and sap discourage strengthen and discourage Full list of antonyms (89) Share this picture Share this image Share this picture Share this image