Remarks made by a person while in conversation with one or more people that may or may not have any bearing on the current subject being discussed.
Slick filler is a manipulation tactic used by a person to camouflage their ignorance about what's being discussed, or to deflect, direct, redirect, dismiss, draw attention too, or mock, what's being discussed.
Slick filler is basically random sound bites injected into conversation at any time, that can be about any subject, for any reason, including no reason at all.
Slick filler can also just be BULLSHIT
M.K. and I couldn't take another minute of Mara and her mind numbing slick filler about Botox, boob jobs, and poetry.