Flanderization

The process by which a single trait from a character is overstated and brandished to the point that it becomes the character's only trait. Flanderization is almost always for the worst and tends to draw viewers away from the the medium that the character represents.

.just like Ned Flanders on the simpsons
every thing is
its gone wet
The act of taking a single (often minor) action or trait of a character within a work and exaggerating it more and more over time until it completely consumes the character. Most always, the trait/action becomes completely outlandish and it becomes their defining characteristic. Sitcoms and Sitcom characters are particularly susceptible to this, as are peripheral characters in shows with long runs.

The trope is named for one of the examples in The Simpsons, Ned Flanders, who was originally just a considerate neighbor and attentive father, with his devout nature simply being that he willingly attended and paid attention in church, all to make him a contrast to Homer, before becoming obsessively religious to the point of stupidity.

Note that the key to this trope is in how the process is a gradual thing, the character starts relatively normal then gains a few quirks, the quirks become more prominent and then gradually become the character. If it is simply about how the character is different early on before the writers know what to do with them, that is Characterization Marches On. Flanderization doesn't have to be a bad thing - sometimes it can be used to expand on a background character's personality when they are brought to the foreground, or make an otherwise bland character stand out more.

The Dutch speaking region of the country Belgium. Inhabitants of this region are called Flemmings (No there isn't a country called "Flemm")The French speaking part of Belgium is called Wallonia.

To attempt a conversation while unintentionally thoroughly confusing your listener. Approving and negating a topic in the same sentence. To open up a conversation on one topic and randomly change to another. The flanderer may be sober or intoxicated. Rapid successions of the words, "yea, yea, yea, no, no, no"

A complete stranger who approaches you at a gas station in the middle of nowhere, only to ask you if you've "found Jesus yet?" The question is usually accompanied by a proselytizing business card depicting someone going to hell for their supposed sins.

Someone who takes christianity too seriously, revolving most or all of their everyday life around God and/or the bible.

Somebody who never does anything wrong, a do-gooder. This person will often seem to good to be true.