1798, "method of printing from a plate," from French stéréotype (adj.) "printed by means of a solid plate of type," from Greek stereos "solid" (see stereo-) + French type "type" (see type (n.)). Meaning "a stereotype plate" is from 1817. Meaning "image perpetuated without change" is first recorded 1850, from the verb in this sense. Meaning "preconceived and oversimplified notion of characteristics typical of a person or group" is recorded from 1922 (Walter Lippmann, "Public Opinion").
compound adjectival word-forming element, usually interchangeable with -ic but sometimes with specialized sense (such as historic/historical, politic/political), Middle English, from Late Latin -icalis, from Latin -icus + -alis (see -al (1)). Probably it was needed because the forms in -ic often took on a noun sense (for example physic). Forms in -ical tend to be attested earlier in English than their twins in -ic.
<a href="https://www.etymonline.com/word/stereotypical">Etymology of stereotypical by etymonline</a>
Harper, D. (n.d.). Etymology of stereotypical. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/stereotypical