Euphemism – a mild or indirect word or expression substituted for one considered to be too harsh or blunt when referring to something unpleasant or embarrassing.

Source: https://www.google.ca/#q=euphemism

Examples:
• You are becoming a little thin on top (bald).
• Our teacher is in the family way (pregnant).
• He is always tired and emotional (drunk).

http://literarydevices.net/euphemism/