It could help to know what you think it means, but as far as I know it does refer to a sexual orgasm. How? Well it is said that when one has an orgasm, one literally "dies" after it happens. Literally translated, it means "the small death".

If you mean "la petite mort" it is an expression used for the noun "orgasm" ; but it is a little more poetic. Otherwise I have no idea what you mean.