Euphemism occurs when a softer, vaguer, or even pleasant expression is used for something that is ugly, negative, or unpleasant. This is only a fallacy if it is used to give a false impression.
"It’s not pro-abortion; it’s pro-choice."
"It’s not government spending; we are making investments."
"We aren’t raising taxes; everyone is paying their fair share."
"It’s not creating dependencies; we are helping the poor."