fermentation

(v) the act of depriving a substance of oxygen while it goes through cell respiration. Several things can come of fermentation,lactic acid in an animal cell and ethanol (alcohol) in a plant cell. In certain plant cells such as grain and grapes adding yeast during the fermentation process can cause it to create desirable alcohol such as wine and different types of hard alcohol or beer. It should be noted that drinking alcohol from grain plain is not practical and it must be added to a substance to create an edible drink e.g. vodka

(v) the act of depriving a substance of oxygen while it goes through cell respiration. Several things can come of fermenttaion,lactic acid in an animal cell and ethanol (alcohol) in a plant cell. In certain plant cellos such as grain and grapes adding yeast during the fermentation process can cause it to create desirable alcohol such as wine and different types of hard alcohol or beer. It should be noted that drinking alcohol from grain plain is not practical and it must be added to a substance to create an edible drink e.g. vodka

Someone who sits on a couch for far too long is fermenting, and should generally be beaten to a pulp and stuffed into a bottle with brewers yeast for two weeks. This creates an incredibly potent and mind numbing alcohol... Goes great with twice baked potatoes.

The act of staying in your room for days at a time, not showering, and avoiding social interaction to the point of becoming a greasy, unhealthy slob. Usually accompanied by heavy use of the internet and/or video games. A fermenter's natural habitat is typically found in the dark corners of sites like 4chan, reddit, and twitch.

Once you start to ferment, it can be hard to get out, usually requiring some sort of wake-up call from the outside world. Some fermenters never get this wake-up call or ignore it, resulting in a lifetime spent mostly in their rooms.

Fermentation can lead to later complications such as depression, anxiety, anti-sociality, obesity, diabetes, and more.

The process in which a woman who regularly partakes in heavy alcohol and drug consumption inserts a tampon into her feminine area and leaves it there for an extended period of time (usually at least three weeks). After enough time has elapsed, another person removes the tampon with his or her teeth and sucks all the accumulated toxin filled fluid from it in order to experience an altered state of mind and body which is said to have no rival.

Means 'fucking mental'.
Has nothing to do with fermentation, fermenting or anything of the like.
fucking+mental=fermental

State of human body when copious amounts of hops, barley, potato, agave or other plant derivitaves have been consumed in excess amounts.