A word that is immediately recognized as a whole and does not require word analysis for identification.

Words that good readers instantly recognize without having to decode them. Sight words are usually "high-frequency" words. Fry's 300 Instant Words may be found here. (PDF file).

A word in a reading lesson containing parts that have not yet been taught, but that is highly predictable from the context of the story or which the child has memorized.

Sight words are common or "high frequency" words, especially in English, that readers should be able to recognize immediately. Teachers often use flashcards to test their students' ability to recognize sight words. For younger children, such flashcards typically have the words on one side and illustrations on the other.