ultra-fast en · ADJ
Etymology
From ultra- + fast.
Meanings
-
(alt-of, alternative, not-comparable) Alternative form of ultrafast.
alt of ultrafast
Less important lines of plain double track carrying a mixture of passenger and freight traffic cannot be given ultra-fast expresses, and where alternative routes exist, as for example between London and the West Riding, the specially high-speed trains must be restricted to one of them only.
1960 February, “Talking of Trains”, in Trains Illustrated, page 67: