Military Health

noun a violent shaking or jarring, especially resulting in an injury to the brain

• He suffered a concussion after falling off his bike without a helmet.
• She got a concussion from hitting her head on the door.
• I heard he got a major concussion from that car accident.
• The team's loss was like a concussion to their championship hopes.

noun an abbreviation for venereal disease, a sexually transmitted infection

adjective used to describe something related to venereal disease

• VD stands for Venereal Disease, which is a sexually transmitted infection.
• I heard she got VD from her ex-boyfriend.
• Don't sleep around or you might end up with VD.
• His reckless behavior is like VD, spreading harm to those around him.