- tangential (adj.)
- 1620s, see tangent (adj.) + -ial. Figurative sense of "divergent, erratic" is from 1787; that of "slightly connected" is from 1825. Related: Tangentially.
- agential
- "Of, belonging, or relating to an agent or agency; that is or acts as an agent", Mid 19th cent. From either post-classical Latin agentia agency, or classical Latin agenti-, stem of agēns + -al; compare -ial.