Definition Of flattest
(of a fee, wage, or price) the same in all cases, not varying with changed conditions or in particular cases.
a $30 flat fare
(of musical sound) below true or normal pitch.
Sung in a deliberately flat tone, this song is a typically acidic musical joke and for that reason it does not stand up to repeated listens.
lacking interest or emotion; dull and lifeless.
“I'm sorry,” he said, in a flat voice
of or relating to flat racing.
the Flat season
smooth and even; without marked lumps or indentations.
a flat wall
Example Of flattest
"This is probably a sedimentary rock made up of particles that have accumulated on a fairly flat surface.
A leaking roof can lead to damage on ceilings and walls, so it is important to replace loose or cracked slates, and get damaged material on flat roofs repaired.
A woman had been driving down a freeway, and had had a flat tyre.
and that's flat
And there does seem to be a pretty flat contradiction between those two points.