When you make a pun by accident, and you don't realise until after you say it.
My girlfriend was sick, so I said to her 'you're pretty hot' (referring to her temperature). It was only afterwards that I realised that what I said could be interpreted as referring to her physical beauty! What a great eigenpun...
A genre of music which portrays self emotion through the medium of instrumental experimentation using mainly rhythms as the basis. Derived from the Physics and Mathematics term "eigenfunction".