noun
Jocular, derogatory slang for Tokyo, formed by analogy with ペキン (Beijing). Used playfully or dismissively, often online or in casual speech.
トンキンに住んでる奴はみんな冷たいよな。
People living in Tokyo are all cold, aren't they.
またトンキン出張かよ、めんどくせえ。
Another business trip to Tokyo? What a pain.