Noun : "To pass away" is a euphemism for "to die.".    From Dictionary.com. 

They are euphemistical as to the weather, calling it hazy and soft, and never allowing themselves to carry bad language on such a subject beyond the word dull.    From Wordnik.com.  [Castle Richmond] Reference

Certainly ... they do not seem to have been a company of gentle, dreamy and euphemistical saints, with a particular aptitude for martyrdom and an inordinate development of affability.”.    From Wordnik.com.  [Anne Bradstreet and Her Time]

Certainly ... they do not seem to have been a company of gentle, dreamy and euphemistical saints, with a particular aptitude for martyrdom and an inordinate development of affability. ".    From Wordnik.com.  [Anne Bradstreet and Her Time] Reference