Fu Shou : Felicity & Longevity
The character fu is "good fortune, blessings, happiness." It denotes being happy as the result of being lucky. The character is prominently displayed on doors, often upside-down, as "turn upside-down" and a word meaning "arrive" are homophones; in other words, to say "luck upside-down" sounds like "luck is coming."
The character shou stands for longevity. In Taoism, life is everything, without which, nothing is left. So the current life (as opposed to the afterlife) is overwhelmingly valued. Thus the desire to live longer is the goal of life.
Shou and fu co-exist; to live long is to have fu.