"Come short of" is a phrase that describes falling just shy of achieving something. Its synonyms include "fall short of", "miss the mark", "come close but no cigar", "be inadequate", "not measure up", "fail to reach", and "lack". These terms can be used interchangeably depending on the context and level of formality required. The phrase can be used to describe situations in which one's efforts or abilities were not enough to achieve a desired outcome. Using synonyms for "come short of" can help to add variety to one's writing or speech, and can help to convey meaning more effectively.