Gormless

[Britney]

Lacking sense or initiative; foolish.

[Rihanna]

stupid or [slow-witted]; adjective - ([Oxford English Dictionary] definition) also describes one who is lacking in [composure], grace, intellect, style etc.
A nick-name for one whose attributes are all of the above.

[Mark Zuckerberg]

[Brainless]. [Lacking] in [intelligence].

[Sarah]

Definition:

1. A lack of intelligence, or a person or thing of less, or [fewer], intelligence.
2. Less than intelligent.

Related form:
[gorm] less - adjective

gorm

• noun. intelligence, intelligent

less (Ref: [www.dictionary.com])
–noun 7. a smaller amount or quantity...
–adjective. smaller in size...

[Lanell]

someone who couldnt [find] their [arse] with both [hands].

[Oralee]

based on [Roald Dahls] [Matilda]: people who arent dull or stupid, but arrogant and [narcissistic]

[Julian]

Someone lacking so much of a clue [they dont know] ass from [tit]. Completely lacking in [gorm].

[Agnes]

A person [wiv] the [inteligence] span of a [dead fish]