morning wood

According to lexicographer Jonathon Green, morning wood has been a US slang term for “an erection of the penis first thing in the morning” since the 1990s. In the UK, morning wood is often called morning glory—and not to be confused with the flower. The 2006 New Partridge Dictionary of Slang and Unconventional English cites the terms in Patricia Munro’s 1997 collection of UCLA slang. On the analogy of the stiffness of a tree or lumber to that of an erection, wood has been a slang term for the penis since the 1950s, used especially in the pornography industry to describe erections.

Morning wood is known in medical terminology as nocturnal penile tumescence (NPT). Produced by the release of a hormone called noradrenaline, NPT is a natural, healthy, and spontaneous occurrence happening several times a night. Many men regularly experience morning wood up until their 50–60s, though it is often associated with young adults.

Popular culture often alludes to morning wood as an in-joke and to flirt with taboos, given how common its component words are. Several bands and albums have taken the name morning wood. In the movie Office Space, the protagonist lives in a complex called Morningwood Condominiums. A level in the first person shooter game Duke Nukem Forever is titled “Morning Wood.” There’s even a morning wood-inspired Halloween costume. Innocent occurrences of morning wood, like the name of street or company, are often the source of laughter among people familiar with the slang.