WEBSynonyms. hold up. carry the weight of. support. bear. carry. prop up. sustain. brace. shore up. buttress. bolster. underbrace. underpin. elevate. raise. In taking the oath of office the President swears to uphold the U. S. Constitution. Synonyms. support. maintain. sustain. preserve. protect. defend. champion. advocate. stand up for. approve.