it means Riddiculous or Nonsensical :)

TUBE is right it means "non-sense" or ridiculous. ไร้ means without สาระ means matter or substance of the topic The opposite would be มีสาระ which means whatever you're referring to has the substance in it = makes sense :)

ไร้สาระ means someone or something that doesn't make any sense. You can say "That cartoon is really ไร้สาระ," or "He always say something ไร้สาระ." If you split the two words apart. ไร้ means without or lack of. สาระ means sense or knowledgeable information.