Memory which is improved by previous experiences, without one’s conscious awareness of this fact. This type of memory is automatic. People who have amnesia lose their explicit memory as opposed to this type of memory. Some examples of things that are categorized as implicit are things your muscles remember how to do (haven’t worked out in a while, but used to be a very involved athlete…your muscles remember how to exercise), rules for playing certain games (even though you don’t remember learning them), and sometimes certain words.
Many types of behavior are the result of implicit memory. What we learn or encounter in the past tends to result in certain ways of doing things or ways of thinking.
Example: Remembering how to ride a bicycle is effortless for most people, even after going years without riding one.
Here is a more in-depth look at implicit memory: http://www.answers.com/topic/memory-implicit-memory