not a bit

a bit

1. A small portion, degree, or amount. It got a bit warm when the sun started shining so I'm not going to need to wear this coat today. I forgot my lunch, can I have a bit of yours? I'm afraid I've caught a bit of a cold.
2. A brief amount of time; a moment. I should be over in five minutes, so I'll see you in a bit!
See also: bit

not a bit

Not a single, tiny bit; not at all. A: "Are you nervous at all about tonight's fight?" B: "Not a bit. This is what I've been training for." I don't get a bit of gratitude from my children for everything you do to keep them happy and healthy. That joke is not a bit funny.
See also: bit, not
Farlex Dictionary of Idioms.

not a bit

none at all; not at all. Am I unhappy? Not a bit. I don't want any mashed potatoes. Not a bit!
See also: bit, not
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

a bit

1. A small amount of anything; also, a short period of time. For example, Here's a bit of wrapping paper, or It'll be ready in a bit, or Just wait a bit. [c. 1600]
2. Somewhat or rather, as in It stings a bit, or Will you have a bit more to eat? [Second half of 1600s] Also see bit by bit; not a bit.
See also: bit

not a bit

Not at all, not in the least, as in She was not a bit interested. [Mid-1700s]
See also: bit, not
The American Heritage® Dictionary of Idioms by Christine Ammer.

not a ˈbit

,

not one (little) ˈbit

not at all: ‘Are you cold?’ ‘Not a bit.’ I don’t like that idea one bit.
See also: bit, not
Farlex Partner Idioms Dictionary

bit

1. n. a jail sentence. (Underworld.) Mooshoo did a two-year bit in Sing Sing.
2. n. a small theatrical part. (From bit part.) It was just a bit, but I needed the money.
3. n. any part of an act; any isolated activity or presentation. I didn’t like that bit concerning penalties.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • a bit
  • a tad bit
  • hard going
  • beg (something) from (someone)
  • beg from
  • bag of fruit
  • in the laundry
  • as bad as all that
References in classic literature
'Not a bit,' replied the Yorkshireman, extending his mouth from ear to ear.