The part of long-term memory dealing with words, their symbols, and meanings.
Semantic memory allows humans to communicate with language. In semantic memory, the brain stores information about words, what they look like and represent, and how they are used in an organized way. It is unusual for a person to forget the meaning of the word "dictionary," or to be unable to conjure up a visual image of a refrigerator when the word is heard or read. Semantic memory contrasts with episodic memory, where memories are dependent upon a relationship in time. An example of an episodic memory is "I played in a piano recital at the end of my senior year in high school."
The "tip of the tongue" phenomenon provides some insight into the way information is stored in semantic memory. Most people have experienced this situation where they are trying to recall a person's name. As the person searches through his or her memory for the name Stern, for example, he or she will recall other similar names—Stone, Stein—but not Douglas or Zimmer. Semantic memory appears to categorize information that has similar meaning (in this case, surnames), that begins with the same letter, and has the same number of syllables.
Words and other memories that are stored in semantic memory contribute to episodic memory and the two work together to function as an effective long-term memory system.
Bolles, Edmund Blair. Remembering and Forgetting: Inquiries Into the Nature of Memory. New York: Walker and Co.,1988.