Unimaginable means too extreme to picture. Unimaginable suffering, unimaginable wealth, almost unimaginable.
It is used of scale at both ends — wealth and suffering both — and it is a confession as much as a description: the speaker cannot hold the thing in mind. It is often followed by an attempt anyway. Note unthinkable, which claims the thing should not be considered rather than cannot be pictured.
1adjectiveunimaginableToo extreme to picture.
“The floods caused unimaginable damage, wiping out whole villages.”
unimaginable is a quality of extremity.
Latin
imāginor
Middle French
imaginer
Middle English
ymagynen
English
imagine
English, today
unimaginable
Built from
From un- + imagine + -able. imagine comes from Middle English ymagynen, from Middle French imaginer, from Latin imāginor, from imāginem, the accusative singular of imāgō (“a copy, likeness, image”).
Etymology from Wiktionary, CC BY-SA