The phrase "puts flea in ear" means to suggest a doubt or suspicion to someone or to imply something negative about someone. Some synonyms for this phrase include "planting a seed of doubt," "casting aspersions," "making insinuations," or "casting a shadow of suspicion." Other similar phrases include "throwing shade," "hinting at something," or "tossing out accusations." No matter the phrasing used, the idea remains the same: to subtly or not so subtly suggest that someone or something may not be trustworthy. It is important to be mindful of the impact our words can have on others and to communicate clearly and honestly.