The term moded (also known as modded, outmoded) is a rare, but complex slang expression that conveys various meanings, depending on the situation.
The most common use of it is when somebody is proven wrong in a debate.
When somebody is moded in an argument, it means that they got publicly embarrassed.
In this case, it is typically used on those who vehemently defended their arguments prior, and were proven wrong.
A more abstract derivative of that meaning is when moded is used as an adjective: if you feel/look moded, it means that you are out of place.
You can also be moded when you hold high expectations towards something but get disappointed at the results.
Sometimes the expression can also refer to a badly taken picture of you.
The etymology of the expression suggests that it is an abbreviation of the word “demoted”, which means to move somebody to a lower rank, usually as a punishment.
It was developed by teenagers in California during the 1790s. Originally it was used as “moted” but pronounced as moded, later its written form shifted to the latter too.
This slang was popular in the 70s and 80s, mostly in the Los Angeles area. There was a rhyme which largely helped in the spread of the expression during those times: “Moded, corroded, your butt exploded.”
Eventually the term started to fade from usage, as the generations familiar with it started to grow older.