The antonyms for the word "laps up" can vary depending on the context of its usage. If "laps up" is used to describe someone's enthusiastic consumption of information, some antonyms could be ignore, disregard, or reject. On the other hand, if "laps up" is used to describe an animal drinking water, some antonyms could be spit out, regurgitate, or reject. In general, antonyms for "laps up" could include words like abstain, decline, or balk, which suggest a resistance or hesitation to take in or accept something eagerly.