Probably from Middle Chinese compound 畫商 (hwɛH syang). Compare modern Chinese traditional 畫商 and simplified 画商 (huàshāng).
Alternately, may have been coined independently in Japan as a compound of Sinitic elements 画 (ga, “picture, painting”) + 商 (shō, “business, dealings; dealer”).
画商 (hiragana がしょう, romaji gashō, historical hiragana ぐわしやう)
- the business of selling pictures
- an art dealer (specific to pictures; does not include sculpture or other media)
- ^ 1998, NHK日本語発音アクセント辞典 (NHK Japanese Pronunciation Accent Dictionary) (in Japanese), Tōkyō: NHK, ISBN 978-4-14-011112-3