¹pattern

model, example, pattern, exemplar, ideal mean someone or something set before one for guidance or imitation. model applies to something taken or proposed as worthy of imitation <a decor that is a model of good taste>. example applies to a person to be imitated or in some contexts on no account to be imitated but to be regarded as a warning <children tend to follow the example of their parents>. pattern suggests a clear and detailed archetype or prototype <American industry set a pattern for others to follow>. exemplar suggests either a faultless example to be emulated or a perfect typification <cited Joan of Arc as the exemplar of courage>. ideal implies the best possible exemplification either in reality or in conception <never found a job that matched his ideal>.

In medieval English a person who served as a model to be copied was called a patron. Some people began to say patron in such a way that the sound of the r changed its place. Patron soon became pattern. After a time pattern, the new way of saying the word, was used just for the meaning “a model to be copied.” The older patron lost that meaning, though it kept its other senses. In this way we got a new word, pattern, from an older word, patron.