Google dictionary has this information about the origin of ex Former is used to describe someone who used to have a particular job, position, or role, but no longer has it Is short for exempli gratia, and is in common use to introduce an example within a sentence
exスペシャルセット | ポケモンカードゲーム公式ホームページ
Submit a sample of academic writing, e.g., a dissertation chapter
However, some authors use ex.
In writing, though, the use of former doesn't seem so rare In informal english, especially us english, it is acceptable to say I saw your ex with this hot dude yesterday Or, she is still in touch with all of her exes.
In legal language i have come across the term ex post facto Isn't ex redundant in this phrase Post facto also means after the fact, so it should be sufficient This is commonly used in
What is the proper way to use the ex prefix to more than one word
My ex baseball coach taught me Ex by itself (no hyphen) doesn't seem right either I would refer to someone in this situation as a former employee Former referring to something that happened in the past (i.e
The person worked for the company in the past) and employee referring to someone who worked for a salary