What does "irreplaceable" mean?

Incapable of being replaced, especially because of uniqueness or finiteness.

Irreplaceable

Common synonyms include: essential, incalculable, indicated, indispensable, inestimable, invaluable.

adj

adj ·5 syllables ·Rare ·Advanced level

Adjective

1
Incapable of being replaced, especially because of uniqueness or finiteness. not-comparable
"irreplaceable batteries"

Adjective

"The time we've spent together is irreplaceable."

From ir- + replaceable.