Explanation of what Kamae (構え) means

According to SCHLATT (2001) The Shotokan-karate dictionary. Michael Götzelmann. Germany, the word Kamae (構え) means: “The fighting position with focus on attack or defence. It can be further distinguished in physical readiness or kamae of the body (migamae) with emphasis on technique (waza), distance (maai), rhythm (hyoshi) and breathing (kokyu) and mental readiness or kamae of the ki (kigamae). This encompasses mainly the alertness (zanshin), fighting spirit (kihaku) and perceptiveness (yomi).” 

Extract from a thesis written by Alta Venter: 
If you think Kamae is only a ready position for kumite, you will lose the true meaning of the word. It is true that Kamae is generally used for all ready positions before starting with kumite, but it is important to understand that this position, like most other areas of karate, should not only be a physical position, it must also be a mental. The Kamae position is thus a “mentally”' ready position as well as a “physically” ready position. It can and should be used in one's everyday life. Kamae must be mentally and physically present in our lives to detect danger and to be able to respond to danger. One must not be “caught off guard”, but you must expect the unexpected. 

In pictures of karate masters and when you watch Sensei Taiji Kase, you will see them standing in Kamae. The masters are not standing in what we today would consider a modern fighting posture. This is because they did not separate the act of kumite from the their normal mental state. This is why their Kamae looks as if they are simply standing there not appearing to be ready for action. In fact they were ready for all action and by not looking at any one thing in particular they see all things clearly. 

One should train to never lose Kamae. It is evident that in true Budo the Kamae is ever present and does not have to look like a fighting posture. In order for you to live Kamae, training must become a part of your life and life must be part of your training.