Bad luck and Set-back

Bad luck noun - An unfortunate state resulting from unfavorable outcomes.

Set-back and bad luck are semantically related. In some cases you can replace phrase "Set-back" with "Bad luck", this phrases are similar.

Set-back noun - Structure where a wall or building narrows abruptly.

Bad luck and set-back are semantically related. Sometimes you can use "Bad luck" instead a noun phrase "Set-back".