swallowtail
swal.low.tail \'swa:l-o--.ta-l, -*-\ \-.ta-ld\ n 1: a deeply forked and tapering tail (as of a swallow) 2: TAILCOAT 3: any of various large butterflies (esp. genus Papilio) with the bor der of the hind wing produced into a process resembling a tail - swal.low-tailed aj