I remember I made a thread once that also was about getting aliases:

http://forums.wowace.com/showthread.php?t=19736
The mentioned Wowpedia page for reference:

http://wow.gamepedia.com/Lua_functions
Code:

local t = {}
for _, v1 in pairs( {math, string, table} ) do
for k, v2 in pairs(v1)do
t[v2] = k
end
end
for k, v in pairs(_G) do
if type(v) == "function" and t[v] then
print(k, t[v])
end
end

I think these are most of the aliases

There don't seem to be aliases for the bit functions

Lua Code:

abs == math.abs

ceil == math.ceil

deg == math.deg

exp == math.exp

floor == math.floor

frexp == math.frexp

ldexp == math.ldexp

log == math.log

log10 == math.log10

max == math.max

min == math.min

mod == math.fmod

rad == math.rad

random == math.random

sqrt == math.sqrt

PI == math.pi

acos ~= math.acos

asin ~= math.asin

atan ~= math.atan

atan2 ~= math.atan2

cos ~= math.cos

sin ~= math.sin

tan ~= math.tan

format == string.format

gmatch == string.gmatch

gsub == string.gsub

strbyte == string.byte

strchar == string.char

strfind == string.find

strjoin == string.join

strlen == string.len

strlower == string.lower

strmatch == string.match

strrep == string.rep

strrev == string.reverse

strsplit == string.split

strsub == string.sub

strtrim == string.trim

strupper == string.upper

foreach == table.foreach

foreachi == table.foreachi

getn == table.getn

sort == table.sort

tinsert == table.insert

tremove == table.remove

wipe == table.wipe