It is a literal fusion of the words in the term:
'Dead Chilling'
Also meaning very relaxed, possibly, high.
An abbreviated version is: Deg (pron. dej, similar to veg)
Mule says 'how are you?'
Katie 'i'm good, feeling quite degilant, thanks, you?'
Mule 'Yeah deg thanks'
by Chantella June 23, 2006
Get the Degilant mug.