Fluff (one's) lines informal slang
To mess a speech up or forget the words that one is supposed to say
I got on my nerves when I delivered my speech in front of hundreds of people, so I fluffed my lines a little bit.
A: "Sorry, sir. I has just fluffed my lines." B: "It's a rehearsal so don't be too worried. You just need to practice more."
Primally used in the UK to indicate the typical manner of communication from the high social class
A person who charms other people with their speech to gain benefits.
If you say something slips your memory/mind, you mean that it is forgotten.
If you lose your train of thought, you forget what you was talking or thinking about.
The verb "fluff" should be conjugated according to its tense.
The first known usage of this meaning derives from British theatrical language in the 1870s when “to fluff one’s lines” means to forget them. It is not known how or why this particular meaning of “fluff” came about. One suggestion is that it might be echoic of the verbal sounds an actor might make in trying to remember lines. The original meaning of “fluff”, of course, is any small piece of fabric or material that is very light, soft and downy, which meaning dates from the late 18th century.
To say the same thing repeatedly
Ok, I get it! You sound like a broken record, seriously!