Definition of nerdiness in US English:

nerdiness

noun

informal
  • 1The quality of being unfashionable and socially inept or boringly studious.

    ‘he tries to incorporate his nervousness and nerdiness into his onstage persona’
    1. 1.1 The quality of being obsessively interested in something, especially technology.
      ‘we salute your nerdiness and love for stats’

Pronunciation

nerdiness

/ˈnərdinəs//ˈnərdēnəs/