micropenis: a birth defect in which the penis is extremely small. The maximum stretched length is not greater than .5 standard deviation units (SDU) below the mean for age, and possibly as small as 5.0 SDU below. The diameter is correspondingly small, with extreme hypoplasia of the corpora cavernosa. As compared with a micropenis, the average adult penis's stretched length is 6.6 inches (16.7 cm), with a standard deviation of 0.77 inches ([1.95 cm) (Money, Lehne, and Pierre-Jerome, 1984) an exceptionally small penis that resembles the clitoris in size. A micropenis may carry the urethral tube or may be hypospadiac. Typically, it is formed mostly of skin, the body (corpora cavernosa) of the penis being hypoplastic. The condition is also known as microphallus or penile agenesis.

Dictionary of Sexology Project: Main Index