Joder. As simple as that, The sexual act, and with all its figurative implications, exactly as in English.
But the verb "joder" has been left by the use as an "out of fashion" term, a dirty word, but actualy it doesn't keeps the primary meaning. Therefore, if you want to call the sexual act by its name, the real one, each Spanish speaking country has a couple of ways to call it.
Making a list of them, is not the scope of this site.