tangential
1. [ adjective ] of superficial relevance if any
Synonyms: digressive
Examples:

"a digressive allusion to the day of the week" "a tangential remark

Related terms: irrelevant
2. [ adjective ] of or relating to or acting along or in the direction of a tangent
Examples:

"tangential forces"

Related terms: tangent
Similar spelling:   tangentially
  tangent
  tangent_plane
  Tanganyika
  tangency
  Tangeman