Definition of nerdgasm in US English:

nerdgasm

noun

informal
  • A thrill of excitement felt in response to something relating to a subject in which a person has an obsessive interest.

    ‘fans would have a nerdgasm at the announcement’

Origin

Early 21st century: blend of nerd and orgasm.

Pronunciation

nerdgasm

/ˈnərdˌɡæzəm//ˈnərdˌɡazəm/