A cushy job or a cushy life is very easy: not much hard work, not much worry, and often quite comfortable. People say it with a little envy, or a little bite — he landed a cushy post at the office. It is informal. In British English you may still hear a cushy number for an easy job. Though actually, it sounds like cushion, and a cushy life does feel soft, but that is not where the word comes from. Soldiers brought it into English from Hindustani khushi, from Persian xuši, a word for happiness. You use it about work, life, postings, deals. You do not use it about a chair; that would be cushioned or comfy.