1824, "leading in one direction only;" by 1887 in reference to travel tickets or fares; 1914 in reference to streets; 1940 in reference to windows, mirrors, etc.; from one + way (n.).
one-way streets
a one-way ticket
one-shot
one-sided
one-stop
one-time
one-upsmanship
one-way
ongoing
onion
oniony
online
onlooker
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