What is "never mind"

Mind \Mind\ (m[imac]nd), v. t. [imp. & p. p. Minded; p. pr. & vb. n. Minding.] [AS. myndian, gemynd[=i]an to remember. See Mind, n.]

1. To fix the mind or thoughts on; to regard with attention; to treat as of consequence; to consider; to heed; to mark; to note. ``Mind not high things, but condescend to men of low estate.''
   --Rom. xii. 16.

   My lord, you nod: you do not mind the play.
   --Shak.

2. To occupy one's self with; to employ one's self about; to attend to; as, to mind one's business.

   Bidding him be a good child, and mind his book.
   --Addison.

3. To obey; as, to mind parents; the dog minds his master.

4. To have in mind; to purpose.
   --Beaconsfield.

   I mind to tell him plainly what I think.
   --Shak.

5. To put in mind; to remind. [Archaic]
   --M. Arnold.

   He minded them of the mutability of all earthly things.
   --Fuller.

   I do thee wrong to mind thee of it.
   --Shak.

   Never mind, do not regard it; it is of no consequence; no matter.

   Syn: To notice; mark; regard; obey. See Attend.

vb. 1 (&lit never mind English) 2 (context imperative English) It is not important; do not fret; (non-gloss definition: used to reassure or comfort the person to whom it is said). 3 (context imperative English) Do not be concerned (about someone or something, or about doing something). 4 (context imperative English) (non-gloss definition: Indicates a withdrawal of a previous statement.) 5 (context idiomatic English) let alone; much less.