might-have-been

plural might-have-beens

1. Someone or something whose potential greatness was not achieved.

   But no more imposing might-have-been was there in Great Britain than the Glasgow & North Western Railway, which was intended to run from Glasgow to Inverness via Glencoe and the Great Glen.

   1955 January, C. Hamilton Ellis, “The Glasgow & North Western Railway”, in Railway Magazine, page 47

   1 more example

   One of the might-have-beens of railway history, however, would have altered the appearance of Monsal Dale considerably. The western portion of the Lancashire, Derbyshire & East Coast Railway (projected in 1891), from Chesterfield to Warrington, was planned to cross the dale and the Midland Line by a viaduct 543 yds. long and 272 ft. above the bed of the River Wye.

   1960 March, J. P. Wilson, E. N. C. Haywood, “The route through the Peak - Derby to Manchester: Part One”, in Trains Illustrated, page 157

   Synonyms: could-have-been