There are numerous synonyms that can be used for the phrase "not thoroughly." Some of the common synonyms for this phrase include inadequate, cursory, incomplete, skimming, superficial, hasty, and partial. These words can be used to describe a wide range of situations where the task or job was not completed with enough attention or focus. For example, a cursory glance might be used to describe a quick glance that isn't very thorough or a superficial cleaning that didn't really get everything. In any case, when using one of these synonyms, it's important to provide additional context to ensure that the intended meaning is understood clearly.