The phrase "skimmed the top" means to take only the superficial or most obvious aspects of something without delving deeper. Some synonyms for this term include "scratched the surface," "touched upon," "covered the basics," "only saw the tip of the iceberg," and "glimpsed." These words all convey the idea that a person has only touched upon or briefly explored a topic without fully immersing themselves in it. It is important to note that while this approach may work for some situations, it is not always advisable, as it can lead to a lack of understanding and superficial knowledge about a subject.