The phrase "gibe at" can be substituted with numerous synonyms depending on the context. For example, the words "mock," "ridicule," "taunt," "jeer," "deride," "tease," and "scoff" all convey the idea of making fun of or belittling someone or something. The phrase "poke fun at" also works as a synonym. However, it's essential to use these words with care as they may take on a negative tone, which can be disrespectful or hurtful to others. In some cases, using a more neutral term such as "criticize" can convey the same message without being insulting. Ultimately, it's crucial to consider the context and audience when choosing synonyms for "gibe at".