What are the laws about cursing someone? How is "cursing" defined?
"Cursing" isn’t the same thing as using improper language; it means saying something like "may G-d smite you" (see Deut. 28:22,27,28,35). "G-d damn you" would probably qualify as a curse. Cursing anyone is forbidden; and cursing G-d or a parent carried the death penalty (in the days when Jewish courts administered death penalties), provided it was done before witnesses and made use of one of the Hebrew names of G-d. [Thus, paradoxically, cursing G-d carried the death penalty only if the unlikely wording "may G-d smite G-d" was used.] When Job’s wife (Job 2:9) tells him "curse G-d and die", she probably means that even if he does it privately, he deserves death and so can expect to die soon, even though the courts can’t punish him. [If someone commits a sin that deserves the death penalty, but the courts can’t convict him (for example, because he didn’t do it before witnesses), his punishment is in the hands of Heaven. If he dies "accidentally", we can assume (though of course we can’t be certain) that his untimely death was Heaven’s way of "executing" him for his sin.]