If you suffer an irretrievable loss — like the death of someone you are close to — that means a loss you may never recover from.

What do you mean by irretrievable?

: not retrievable : impossible to regain or recover.

What does irretrievably in love mean?

a humorous way of saying that someone doesn't like or love the speaker. E.g.: You've seen the way she treated me last time we met. It's clear: she loves me not. ILY abbr. acron.