A small pennon borne on a lance.

绑在上小狭长三角旗。

He has had his lance stuck up with a pennon, which streams in a strong east wind.

他那矛枪上扎着一面小三角旗，在强劲的东风中飘动。

The OED says "couch potato" originated as American slang, meaning "a pennon who spends leisure –time passively or idly sitting around, especially watching television or video tapes" .

牛津英语字典解释“沙发土豆”起源于一美国俚语，表示“一位身着燕尾服的人消极地或懒散地坐着度过悠闲的时光，主要是看电视或录像带”。