sunk cost

Noun

(economics) A cost that has already been incurred and which cannot be recovered to any significant degree.

Japanese Meaning

埋没費用：すでに発生し、回収が困難または不可能な費用 / 既払い費用：既に支出され、既に消費された費用で、今後の意思決定に回収の影響を与えない費用

The team kept investing in the failing app because they couldn't accept the sunk cost.

チームは埋没費用を受け入れられなかったため、失敗しているアプリへの投資を続けた。

Sense（1）

(economics) A cost that has already been incurred and which cannot be recovered to any significant degree.

sunk costs

（ plural ）