The Oxford Thesaurus An A-Z Dictionary of Synonyms - immaterialadj.

1) unimportant, inconsequential, nugatory, trivial, trifling, petty, slight, insignificant, slight, flimsy, light, unessential, non-essential, of little account or value: Whether he stays or goes is immaterial to me. 2) airy, incorporeal, disembodied, ethereal, ephemeral, evanescent, unsubstantial: The concept of immaterial matter, such as a gas, is difficult to comprehend.