the short form. It's just a convenient abbreviation, a little bit of
Because, for Lua in particular, there is a resistance to convenience and sugar. Not a refusal to ever consider it, but Lua is remarkably free of cruft and I for one would prefer it stayed that way.
lambda would be OK if you are familiar with the lambda calculus and/or Lisp etc. I suspect that's actually a tiny proportion of the Lua user base (although it includes me), and for the rest it will be just a wacky and confusing term.
/bring bar car and cadr.