lit., "a meeting together with, a coincidence of circumstances, a happening," is translated "chance" in Luk 10:31. but concurrence of events is what the word signifies, rather than chance.
Note: Some texts have tucha here (from tunchano, "to happen").
<2,,5177,ei tuchoi> lit., "if it may happen" (ei, "if," tunchano, "to happen"), signifies "it may chance," 1Co 15:37.