Sentence:  Never had I experienced such an immense slow <WSD>orgasm</WSD> – its ripples ran like the tributaries of the Nile throughout the whole nervous system. 
Meaning of the word marked with <WSD> tags:  A rush of sexual excitement; now specifically, the climax or peak of sexual pleasure, which occurs during sexual activity and which in males may include ejaculation and in females vaginal contractions. (from 18th c.)