- (idiomatic) Two or more people who encounter one another in a transitory, incidental manner and whose relationship is without lasting significance; two or more people who almost encounter one another, but do not do so.
- (idiomatic, by extension) Things which have no significant connection or commonality.
- Often used in the prepositional phrase "like ships that pass in the night".
From a poetic metaphor by Henry Wadsworth Longfellow (1807-1882):
- 1874, Henry Wadsworth Longfellow, Tales of a Wayside Inn, part 3, section 4:
- Ships that pass in the night, and speak each other in passing,
- Only a signal shown and a distant voice in the darkness;
- So on the ocean of life we pass and speak one another,
- Only a look and a voice, then darkness again and a silence.