Funny enough, spirit being defined as meaning both 'inspiration' and 'emotion', seems to predate the 'magical being' definition.
http://www.etymonline.com/index.php?term=spirit
Also, I wasn't aware that being non-religious meant you couldn't be acquainted with these fantastic books known as 'the thesaurus' and 'the dictionary.' Besides being useful in general, in them you learn that most words have established multiple meanings. It turns out that the English language doesn't bow to the whims of any random individual.
My familiarity with them is probably why I knew that 'spirit' was a noun, verb,
and an adjective. Clearly I've been doing this atheism thing all wrong.