Pass away
Definition 1 of 1
Pro Tip 1/3Euphemistic Expression
Used to softly express the fact someone has died, often to be more sensitive or respectful. 
After a long illness, he passed away surrounded by family.
Pro Tip 2/3Cultural Sensitivity
In some cultures, direct mentions of death are avoided, so 'pass away' can be a more acceptable choice. 
In our community, we say that elders pass away, rather than use harsher terms.
Pro Tip 3/3Not for Animals
While it can be used for pets, 'pass away' is usually reserved for humans. 
Our beloved dog passed away after fourteen years with us.