这是一个特点–'蚕头和燕子的尾巴”。

This is one of the characteristics – 'silkworm's head and swallow's tail'.

youdao

任何尾巴有点方且成叉形、翅膀长而尖的燕子；大约在圣马丁节前后迁移。

Any of various swallows with squarish or slightly forked tail and long pointed wings; migrate around martinmas.

youdao

（特别是指蝴蝶和鸟）有像燕子一样的分叉的尾巴。

Deeply forked or notched, as the tails of certain birds.

youdao

（特别是指蝴蝶和鸟）有像燕子一样的分叉的尾巴。

Deeply forked or notched, as the tails of certain birds.

youdao