Definition from Wiktionary, the free dictionary
Usage notes 
In English, the suffixes -ever and -soever may be added to what, which, who, and whom to obtain indefinite pronouns.
- Example: "any" and "some" in "If there's any more, I want some."
- Example: "whomever" in "Bring whomever you wish."
Pronoun not specifying the identity of its referent