ditchwater

[ dich-waw-ter, -wot-er ]

/ ˈdɪtʃˌwɔ tər, -ˌwɒt ər /

water, especially stagnant and dirty water, that has collected in a ditch.

dull as ditchwater. dishwater(def 2).

Origin of ditchwater

1275–1325; Middle English. See ditch, water

"They're as dull as ditchwater, the whole gang of them," he said.

The Trembling of a Leaf |William Somerset Maugham
Dull as ditchwater, you'd think; but no, I don't find it so.

Crome Yellow |Aldous Huxley
He looks as though hes so nice hell be as dull as ditchwater.

Famous Flyers |David Goodger (goodger@python.org)
Life would be as ditchwater were it not stirred to its depths by K.'s secret cable.

Gallipoli Diary, Volume 2 |Ian Hamilton

And, you know this place is as dull as ditchwater unless one does something.

The Hermit of Far End |Margaret Pedler

ditchwater

/ (ˈdɪtʃˌwɔːtə) /

stagnant water

as dull as ditchwater or ditchwater extremely uninspiring