What is the meaning of Whatever?

What ever; emphatic form of 'what'.

Regardless of the ... that; for any ... that.

Any ... that; of no matter what type or kind that.

Any; of no matter what type or kind.

What ever; emphasised form of 'what', used to ask which thing, event, circumstance, etc.

Regardless of anything that.

Anything that; all that.

Anything; thing(s) of unspecified kind, or no matter what kind; sometimes used to indicate that the speaker does not care about options.

At all; in any way; whatsoever.

In what way; to what extent.

A holophrastic expression used to dismiss something that the speaker doesn't care about, doesn't think important, or doesn't want to consider or discuss any further.

Unexceptional or unimportant; blah.

Something whose exact kind or nature is unimportant; a thingy.

Source: wiktionary.org