The word geekgasm, which I spotted in this Guardian piece today, hasn’t yet made it into the OED. Geekgasm is an exciting experience caused by something very nerdy or geeky.
Interestingly, there is only one word ending –gasm in the OED, and that is orgasm. This word comes from the Greek ὀργᾶν (pronounced 'organ'), meaning 'to swell with sexual desire, be excited or eager. Ultimately it comes from the Proto-Indo-European (PIE) root *wrōg-, meaning to burgeon or swell with strength'. I cannot find any other English cognates. The English words orgy and organ, which begin similarly, are related to the Greek ἔργον work, and ultimately stem from the PIE root *worg- or *werg-. The OED tells us that the singular orgy was rare before the 19th century. It entered English from Middle French as a plural, meaning “Secret rites or ceremonies practised in the worship of various gods of Greek and Roman mythology; esp. those practices connected with the festivals in honour of Dionysus or Bacchus” (from OED).