There is no canon word but you can use canon words to describe it, for example you could say "daar strunmah ni mal" "this mountain (is) not small", or you could use the prefix "vo" meaning "un-" to say "vomal" "unsmall" which would work in place of "giant". If you're referring to the creature giant you could still use these words and just put "mun" "man" after them.

I don't think there is a cannon word so just use Mulmun which is just streagth and man mashed together if you're writing something