A term for words used out of habit
Solution 1:
I've heard the term verbal tic used in this context, for habitual expressions that the speaker jams into sentences irrespective of meaning or sense; I overheard one a man say:-
"To be honest with you, Spurs won 2-0. You know what I mean?"
As no-one could doubt his honesty in reporting a football score, or entertain any doubts as to the meaning, I'd guess this is the sort of phrase you are interested in. He'd add one (or both) of those little fragments to practically everything he said.
Solution 2:
It's not a linguistic term, but I think the phrase habitual vocabulary conveys what you're looking for.
Solution 3:
I'd say impulse words or reflex words. Sometimes mothers say their kids regurgitate bad language, and regurgitation comes when the gag reflex activates. So..., 'reflex' words. And, when you do something on impulse, it happens automatically. For example, when you step on a nail, you jump up into the air, 'on impulse'/automatically. If you impulsively yell 'wtf', then you're having an 'impulse reaction', thus 'impulse words'.
You might also look into some words like instinctive and involuntary, or even subconscious and intrinsic, to build a broader syntax.
There's also an off chance you're thinking of Freudian Slips, or 'slips of the tongue'.