noun
Royal Horticultural Society; RHS
Proper noun referring to the UK-based charity and its activities.
王立園芸協会はチェルシーフラワーショーを主催している。
The Royal Horticultural Society organizes the Chelsea Flower Show.
Compound of 王立 (royal), 園芸 (horticulture), and 協会 (society/association), directly translating the English name.