non-optional en · ADJ
Etymology
From non- + optional.
Meanings
-
(alt-of, alternative, not-comparable) Alternative form of nonoptional.
alt of nonoptional
BR offered discounts on round trips to encourage optional days out and weekends away, but it did not want to discount one-way tickets which were typically used for non-optional journeys.
2020 December 2, Mark Smith, “Why fares reform is essential... and why it won't be easy”, in Rail, pages 34–35: