polka dot       
noun [ C usually plural ] uk/ˈpɒl.kə ˌdɒt/ us/ˈpoʊl.kə ˌdɑːt/
 (衣料上的)圆点花纹
one of a large number of small, round spots that are printed in a regular pattern on cloth
  a shocking pink dress with white polka dots 带有白色圆点花纹的艳粉色连衣裙 
 a polka-dot bikini/bow tie 圆点花纹比基尼泳装/领结