elephant trunk

plural elephant trunks

1. astronomyAn extended pillar-like mass of interstellar gas and dust found near a massive star.

   However, the behaviour of the molecular emission in elephant trunks and cometary globules clearly indicated the presence of neighbouring massive stars […]

   2012, Charles J. Lada, N.D. Kylafis, The Physics of Star Formation and Early Stellar Evolution, page 314

2. slangAn uncircumcised penis.

   Just take the weird look of an uncircumcised penis! ('Anteater' or 'Elephant-Trunk')

   1999, Brian J. Morris, In Favour of Circumcision, page 76

   1 more example

   Additionally, jokes geared toward the uncircumcised penis — that is, calling the foreskin an elephant trunk — with no comparable disparaging language ever applied to the circumcised penis points to the idea that an uncircumcised penis is still a deviant genital form.

   2010, Shirley R. Steinberg, Michael Kehler, Lindsay Cornish, Boy Culture: An Encyclopedia (page 129)

3. Used other than figuratively or idiomatically: see elephant, trunk.