Is appropriately used only when specific dates are not known or disputed. (I'll concede to my betters about the usage of circa I would not say It is generally appropriate. Ordinarily You simply see it for dates (as an example, "she was born circa 1920"). The Wiktionary post on 'circa' https://trenbolone-enanthate-dosa01233.bloguerosa.com/36104869/steroids-for-sale-in-usa-fundamentals-explained