"Jackdaw in peacock's feathers" is a metaphorical phrase used to describe someone or something that appears to be more impressive or important than they really are. Synonyms for this expression include "wolf in sheep's clothing," "false front," "pretense," and "showing off." Other related phrases include "flash in the pan," "coat of arms," and "putting on airs." These terms are often used to describe individuals who are pretending to be someone they are not or trying to impress others with their outward appearance or possessions. Ultimately, "jackdaw in peacock's feathers" is a reminder that appearances can be deceiving and it is important to look beyond the surface to understand what is really going on.