Merriam-Webster's Collegiate® Dictionary, 11th Edition
WHATEVER
I. pro noun
Date: 14th century
1. anything or everything that , no matter what , whatnot , what 1a(1),
II. adjective
Date: 14th century
1. any…that ; all…that , no matter what , of any kind at all,
III. adverb
Date: 1870
in any case ; whatever the case may be