Stationery vs. Stationary

How to remember the difference between the words stationery and stationary?
The easiest way is to remember that the “e” in stationery is associated with envelope.

A Definition of stationery
• noun [U]
• The items needed for writing, such as paper, pens, pencils and envelopes
• Good quality paper for writing letters on and matching envelopes

A Definition of Stationer
• Noun [C]
• A person or business that sells stationery

A definition of stationer's
• Noun [C] UK
• A shop which sells stationery

A Definition of Stationary
• Adjective
• Not moving, or not changing
• A stationary car/train
• The traffic got slower and slower until it was stationary.
• The rate of inflation has been stationary for several months.