1) Empty 2) Gratuitous 3) Hollow 4) Idiotic 5) Inane 6) Incomprehensible 7) Mindless 8) Nonmeaningful 9) Nonsense 10) Pointless 11) Purposeless 12) Ridiculous 13) Unimportant 14) Unmeaning 15) Useless 1) Empty 2) Having no significance 3) Hollow 4) Insignificant 5) Mindless 6) Nonmeaningful 7) Nonsense 8) Nonsensical 9) Pointless 10) Purposeless 11) Senseless 12) Unimportant 13) Unmeaning 14) Vacuous 15) Without any significance 
[adj] - having no meaning or direction or purpose
nonmeaningful adjective having no meaning or direction or purpose; `a meaningless endeavor`; `a meaningless life`; `a verbose but meaningless explanation`