(形容詞) 對災難、苦難、痛苦、不幸和困苦等漠不關心、無動於衷或視而不見的。

Research by psychologists suggests Britain is very far from a "walk on by" culture.

Mark Levine, of Lancaster University, studied thousands of hours of CCTV footage of late night violence, and found that in the great majority of cases people do step in and try to defuse violent situations.
—"Intervene or walk-on-by? What would you do when confronted by an act of violence and a victim in need of help?," South Wales Evening Post, April 12, 2013

The image is shocking. For an hour, a little girl, clutching her doll, stands in a crowded shopping centre, clearly lost and appealing for help. But none of the adults stops. Hundreds ignore her until a kindly grandmother, who had already walked past, turns round and asks the seven-year-old if she is all right.

This is the scene to be witnessed on Little Girl Lost, a Channel Five documentary that purports to demonstrate how we have become a "walk-on-by" nation cowed by paedophile hysteria, suffocating criminal records checks and an irrational suspicion of all adult males
—Phillip Johnston, "Would you help a lost girl, or just walk on by?," The Telegraph, March 24, 2014