swallowtailnoun [ C ]
/ˈswɒl.əʊˌteɪl//ˈswɑː.loʊˌteɪl/a type of large colourful butterfly
swallowtailadjective
/ˈswɒl.əʊˌteɪl//ˈswɑː.loʊˌteɪl/having a shape that is divided into two at one end, so that it has two points:
The flag has a swallowtail shape.
used to describe a jacket or coat that has two long pointed parts at the back :
He wore a white bow tie and a swallowtail coat.