Some synonyms for the phrase "curious idlers" include "inquiring loiterers," "inquisitive onlookers," "meddling observers," and "nosy bystanders." These phrases allude to individuals who are passively interested in or engaged with their surroundings, observing and exploring without much purpose or direction. While these terms might have a negative connotation, they can also be used in a positive sense to describe individuals who are curious about the world around them and eager to learn more. Ultimately, the term "curious idlers" captures a sense of intrigue and idle fascination that can also be seen as a valuable aspect of intellectual curiosity and exploration.