Less than a good omen for the millennium? (4)
I believe the answer is:
dome
'the millennium?' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'less than a good omen' is the wordplay.
'DOME' is hidden within the letters.
But, I am unsure how this is indicated.
'for' is the link.
Can you help me to learn more?
(Other definitions for dome that I've seen before include "Hemispherical roof" , "Rounded vault of a roof" , "Rounded roof with circular base" , "A stately building" , "Hemispherical structure" .)