grooveless

As a noun terms

is .

As an adjective grooveless is

without a groove or grooves.

Ungrooved is a synonym of grooveless.

As adjectives the difference between ungrooved and grooveless

is that ungrooved is without a groove or grooves while grooveless is without a groove or grooves.

As a noun groove

is a long, narrow channel or depression; eg, such a slot cut into a hard material to provide a location for an engineering component, a tyre groove, or a geological channel or depression.

As a verb groove

is to cut a groove or channel in; to form into channels or grooves; to furrow.

As an adjective grooveless is

without a groove or grooves.