The Rice University Neologisms Database

Etymology : Nub has relation with "newbie" (which has an etymology in itself). It apperas to have followed the path outlined in the "definitions" section, namely beginning with newbie, which lost the suffix -ie to clipping, then assimilation in the vowel sounds/spelling in the middle of the word (ew-oo-u), resulting in a pronunciation change. This word is common among gamers, and may provide some insight into its formation. When you type out this insult on the screen, it is usually while the game is still going on, so you want to type the word as quickly as possible so you can get back to the game. This could explain the clipping and subsequent change in spelling from two vowels forming a single sound ('oo') to one ('u'). The assimilation of the long 'u' to short 'u' was probably the result of people beginning to speak the word 'nub', as this is how 'normal' english speakers would pronounce it. This word pattern also shows some generalization, as the word newbie usually meant 'newcomer', and, subsequently, someone who lacks skill or experience. The word seems to have moved on to mean someone with sub-par skills, regardless of if they are new to the game or not. The origin of this word can be traced to newbie, which is a result of affixation of -bie (N) to the root new, forming the word.