The AI-powered English dictionary
(idiomatic) Immediately when sighted. quotations examples
"Permissive" working allows more than one train to be in a block section at one time but trains must be run at low speed in order to stop on sight behind the train in front. Such working is often authorised to allow freight trains to "bunch" together to await a path through a bottleneck instead of being strung out over several block sections, as would be necessary if absolute working were in force.
1962 October, “Talking of Trains: The collisions at Connington”, in Modern Railways, page 232
(by extension) Immediately something has come to one's attention. examples
plural on sights
(climbing) An ascent of a route without falling, on the first attempt, without having been advised on it or having seen it prior. examples