matter of time

Noun

idiomatic uncountable

(idiomatic) An inevitable result; something that is bound to happen.

Japanese Meaning

必然的な結果、避けられない出来事 / いつかは必ず起こる、不可避な事態

It's only a matter of time before the old bridge collapses.

古い橋が崩壊するのは避けられない結果だ。

Sense（1）

(idiomatic) An inevitable result; something that is bound to happen.

In a matter of time it would slip from my mind / In and out of my life, you would slip from my mind / In a matter of time