This is the 7051st most frequent Russian word.
безвозвратные
Irrecoverable.
In this sentence, 'безвозвратные' describes moments that cannot be recovered or brought back.
Эти безвозвратные моменты жизни нужно ценить.
These irrevocable moments of life should be cherished.
Here, 'безвозвратные' is used to refer to money that cannot be refunded.
К сожалению, деньги после этой покупки стали безвозвратными.
Unfortunately, the money became non-refundable after this purchase.
In this case, 'безвозвратное' is used to describe a decision that cannot be undone.