of superficial relevance if any;
"a digressive allusion to the day of the week"
"a tangential remark"
(of e.g. speech and writing) tending to depart from the main point or cover a wide range of subjects;
"amusingly digressive with satirical thrusts at women's fashions among other things"
"a rambling discursive book"
"his excursive remarks"
"a rambling speech about this and that"