\version "2.19.83" extremelyLongNameFunction = #(define-music-function (music) (ly:music?) (let ((varOne #{ a b b a #})) #{ $varOne $music $varOne #}))
#(define anAlias extremelyLongNameFunction) \anAlias { c c c c }
That's just Scheme coding, not special in lilypond.