A gentler expression
A euphemism is a milder or less direct expression used instead of one that might sound blunt, awkward or offensive. It changes how something is said, rather than necessarily changing the thing itself.
Think of words putting on soft slippers before entering the conversation.
The powder-room puzzle
Merriam-Webster gives “powder room” as a euphemism for a lavatory. Nobody is checking whether you brought a powder puff.
Another example is saying someone was “let go” instead of “fired”. The wording softens an uncomfortable subject.
Same car, softer label
Imagine two signs beside the same car: “used” and “pre-owned”. The dictionary defines pre-owned as secondhand or used.
In this example, “pre-owned” gives the label a gentler feel. It does not tell you whether the engine is any better.
Listen for the substitution
Ask yourself: what more direct expression could replace this phrase, and why might the speaker avoid it? That makes the softening easier to notice.
For another way words take a detour, explore idioms such as “a piece of cake”. Context helps you work out what someone means.