Before studying psychology, I had never come across this word, but now it's one of my favourites. Buried within the word is a world of meaning to a psychological/social being such as ourselves.
The first step to comprehension of a word is to know its history or etymology. In a sense, we may ask what philosophical or psychological consideration provided the necessity for the word to exist.
The first part of the word is extremely common: de- This 'de-'is a prefix that indicates either removal or negation (Dictionary.com, 2022).
The '-cathect' part of the word comes from a Greek word meaning 'to keep' or 'to hold on to'.
As seen from the etymology of the word, to decathect would be 'not holding on to' or 'not keeping'. In psychology, to decathect is a sort of defense mechanism. It is a way of protecting one's emotional wellbeing in the prospect of some loss.
The easiest way to explain the psychological term decathect, is to consider what might happen when we know someone who is dying, we may feel that we are not capable of dealing with this prospect and begin the process of detaching ourselves emotionally from the individual whilst they are still living.
Quite literally, to decathect is to withdraw emotionally when anticipating a loss.
Some words encapsulate various human vulnerabilites, and this one for me perfectly describes the existential crisis of what it means to be human and the expectation of loss. This word isn't solely used for the example I provided and there are many more mundane examples one of which is provided by the online dictionary.
However, for me, the power of the word 'decathect' lies in its ability to describe the fundamental nature of expected loss.
Dictionary.com - 'Decathect' (2022) (URL) Available at: https://www.dictionary.com/browse/decathect