2. Any remark which telegraphs the solution of a problem or puzzle, thus denying the reader the pleasure of working out the correct answer (see also interesting). Either sense readily forms compounds like total spoiler, quasi-spoiler and even pseudo-spoiler.
By convention, articles which are spoilers in either sense should contain the word ‘spoiler’ in the Subject: line, or guarantee via various tricks that the answer appears only after several screens-full of warning, or conceal the sensitive information via rot13, spoiler space or some combination of these techniques.