noun which may take the genitive case particle 'no', noun
Western-style; Western-fashioned
Describes something done or made in a Western manner, often contrasted with Japanese or traditional styles. Common in contexts like architecture, clothing, ceremonies, and systems.
彼らは西洋式の結婚式を挙げた。
They had a Western-style wedding.
このホテルは西洋式の朝食を提供している。
This hotel serves a Western-style breakfast.
洋式 is a shorter synonym for 'Western-style', often used in the same contexts (e.g., 洋式トイレ). 西洋式 is slightly more explicit about 'Western' as opposed to just 'foreign'.
Compound of 西洋 (せいよう, 'the West; Western') and 式 (しき, 'style; ceremony; formula'). The reading is standard on'yomi.