Euphemist

[yoo-fuh-miz-uh m] /ˈyu fəˌmɪz əm/

noun
1.
the substitution of a mild, indirect, or vague expression for one thought to be offensive, harsh, or blunt.
2.
the expression so substituted: “To pass away” is a euphemism for “to die.”.
/ˈjuːfɪˌmɪzəm/
noun
1.
an inoffensive word or phrase substituted for one considered offensive or hurtful, esp one concerned with religion, sex, death, or excreta. Examples of euphemisms are sleep with for have sexual intercourse with; departed for dead; relieve oneself for urinate
2.
the use of such inoffensive words or phrases
n.

1650s, from Greek euphemismos “use of a favorable word in place of an inauspicious one,” from euphemizein “speak with fair words, use words of good omen,” from eu- “good” (see eu-) + pheme “speaking,” from phanai “speak” (see fame (n.)).

In ancient Greece, the superstitious avoidance of words of ill-omen during religious ceremonies, or substitutions such as Eumenides “the Gracious Ones” for the Furies (see also Euxine). In English, a rhetorical term at first; broader sense of “choosing a less distasteful word or phrase than the one meant” is first attested 1793. Related: Euphemistic; euphemistically.
euphemism [(yooh-fuh-miz-uhm)]

An agreeable word or expression substituted for one that is potentially offensive, often having to do with bodily functions, sex, or death; for example, rest room for toilet, lady of the evening for prostitute. The Nazis used euphemism in referring to their plan to murder the world’s Jews as “the Final Solution.”