There are various synonyms for the phrase "diddled around" which refers to wasting time or procrastinating. Some alternatives to "diddled around" include the phrases "loafed about," "frittered away," or "lazed around." Other synonyms include "dawdled," "lingered," "loitered," and "wasted time." Additionally, "messed around," "faffed about," and "twiddled one's thumbs" can also be used as alternatives. Whatever the synonym used, the main idea is to express that an individual is procrastinating, wasting time, or not making productive use of their time.