earnest
A seven-letter word meaning serious and eager could be "earnest".
counsel
Debacle
A seven letter word for lasts is endures.
The seven letters, mcuanst, can be formed into the seven letter word, sanctum. Sanctum is an English word meaning 'a sacred place.'
earnest
A seven-letter word meaning serious and eager could be "earnest".
You are serious.
Gravest.
tragedy
The second letter of the seven letter word meaning "one-fourth" is "u." The word is "quarter."u as in quarter
A seven-letter word meaning 'including everything' is 'overall'.
surreal
missing
counsel
desired
uncover