Answer: greyest

AnswerCrossword Clue
GREYESTCloudiest, in London
GREYESTMost dreary and cloudy.
GREYESTDullest.
GREYESTMost dismal, British style.
GREYESTMost griseous
GREYESTMost dreary
GREYESTMost dull, in Dover
GREYESTCloudiest, in England
greyestgray
greyestGREY, between black and white, also GRAY