The proposal looked impressive, but the board found its supporting data insubstantial and vague.

這份提案看起來很亮眼，但董事會認為它的佐證資料空泛又模糊。

Customers complained that the hotel's promised ocean view felt insubstantial, just a distant blue haze.

顧客抱怨飯店承諾的海景虛無縹緲，只是一片遠方的藍色霧氣。

Without signed contracts, the partnership remained insubstantial, more an idea than a real deal.

沒有簽訂合約，這項合作始終虛而不實，比較像構想而非真正的交易。