In a manner that is even and without bumps

सुगमता से

English Usage: She glided smoothly across the ice.

Hindi Usage: वह बर्फ पर सुगमता से滑 गई।

Having a surface free from roughness or irregularities

चिकना

English Usage: The surface of the table is smooth.

Hindi Usage: मेज की सतह चिकनी है।