tan·gen·tial 
(tăn-jĕnshəl) also tan·gen·tal (-jĕntl)
(tăn-jĕnshəl) also tan·gen·tal (-jĕntl)adj.
1. Of, relating to, or moving along or in the direction of a tangent.
2. Merely touching or slightly connected.
3. Only superficially relevant; divergent: a tangential remark.
tan·gen′ti·ali·ty (-shē-ălĭ-tē) n.
tan·gential·ly adv.