Flat, even, level, are all synonyms for smooth.
Smooth is an adjective. Smoothly is an adverb.
She touched his smooth face. - adjective. (describes the noun face)
They danced smoothly around the dance floor - adverb (gives more information about the verb dance)
smooth endoplasmic reticulum
Flat can be a noun:I have a flat on my car.When used to modify another word, it is not a noun:I have a flat tire on my car.
bland, dull, flat, weak
Collapsed. Pancaked Crashed Toppled
The comparative of plain is 'plainer' and the superlative is 'plainest'.
The flat surface felt smooth.
Other words for 'flat' are... even, level smooth, equal.
Flat, even.
flat
A flat.
a platue
SegueTransition
buttery, soft, smooth
bumpy, rugh
Tranquil, serene.
another word for horizontal is modif
It means smooth, or flat