Smooth : having an even and regular surface; free from perceptible projections, lumps, or indentations.Indifferent : having no particular interest or sympathy; unconcerned.Gainful : serving to increase wealth or resources; providing money or other benefit.Rough : having an uneven or irregular surface; not smooth or level.Glib : (of words or a speaker) fluent but insincere and shallow; smooth-talking.Synonym of Glib is Smooth