Piddle away is a colloquial term used to describe the act of mindlessly wasting time or engaging in trivial activities. The word piddle can be replaced with several synonyms such as tinker, dally, trifle, or fritter away. Tinkering implies engaging in small and unimportant tasks without making any significant progress. To dally is to indulge in frivolous activities without any sense of urgency. Trifling is to engage in unimportant activities without any real purpose. Frittering away time suggests spending time on unimportant things, resulting in a wasted opportunity. In essence, piddle away and its synonyms all describe the same thing, which is spending time on activities that are of no real consequence.