Stolperstein

Etymology
From. Sense 3 developed in the first decade of the 21st century, applying the figurative sense of "impediment, obstacle" back to literal blocks, though ones that cause passersby to pause and reflect rather than literally stumble.

Noun

 * 1)  stumbling block raised or uneven stone or paving slab over which someone could stumble
 * 2)  pitfall, obstacle, hindrance, stumbling block
 * 3)  stolperstein small, cobblestone-sized memorial for an individual victim of Nazism
 * 1)  pitfall, obstacle, hindrance, stumbling block
 * 2)  stolperstein small, cobblestone-sized memorial for an individual victim of Nazism
 * 1)  stolperstein small, cobblestone-sized memorial for an individual victim of Nazism
 * 1)  stolperstein small, cobblestone-sized memorial for an individual victim of Nazism