ラスボス

Clipping of ラストボス (rasuto bosu), in line with the common Japanese word-formation pattern for compounds, of keeping two morae from each constituent part. Compare パソコン (pasokon), ワープロ (wāpuro).

First appearance is uncertain, but probably some time in the mid-2000s.

• IPA^(key): [ɾa̠sɨᵝbo̞sɨᵝ]

ラスボス • (rasubosu) 

1. [from mid-2000s] (video games) clipping of ラストボス (rasuto bosu, “last or final boss”)
   • 2013 March 25, Yūji Shiozaki, “第百四拾四話 [Chapter 144]”, in 一騎当千, volume 21 (fiction), Tokyo: Wani Books:

     ラスボス関さん登場ってトコか…しっかし　ウワサどおりエロイ体しとる…一分後　そのパイオツの上でワイの舌がダンスするでぇ

     Rasubosu Kan-san tōjō tte toko ka... Shikkashi uwasa-dōri eroi karada shitoru... Ippungo sono paiotsu no ue de wai no shita ga dansu suru dē

     Kan-san, de last boss, has finally arrived... Dayum, what dey say is true, you really are hot... In just a minute, mah tongue will be dancin' on dem tits o' yours