Clitoris is derived from the Greek word for clitoris, kleitoris, which in turn comes from kleio (to close, as with a door or latch), perhaps in reference to those portions of the labia minora that enclose the clitoris, or to the clitoris as a metaphorical gateway to the vagina.
Some have suggested that clitoris may be derived from the Greek verb for tickle, kleitorizein (the German word for clitoris is der Kitzler, the tickler). However, kleitorizein may be dervied from Kitzler (kleitorizein also means "to touch the clitoris").
Gabriele Falloppio (of Fallopian tube fame) was the first to systematically describe the external anatomy of the clitoris back in the 16th century.
The clitoris is rarely represented in its entirely in textbook diagrams and anatomical models. The average length of the adult clitoris from the visible glans to the embedded ends of the crura (which attach to the bones of the pelvic girdle) is about 4".
The clitoris surrounding the penis during intercourse.
The outer layers of the woman's skin and fat are not shown and the
penis is represented as a feature-less cross-section. The ascending
portion of the clitoral shaft can be seen above the glans (the glans is the
portion usually visible). The shaft bends posteriorly at its apex
and divides into the two "legs" (crura ) which encircle the vaginal opening
and the penis.
Drawing by Robert Latou Dickinson, in Human Sex Anatomy, 1949.
Lateral view of the clitoris
This diagram is from a US college website, but I lost the link.
If anyone knows, please leave a comment.