1.
If someone shoots down an aeroplane, a helicopter, or a missile, they make it fall to the ground by hitting it with a bullet or missile.
They claimed to have shot down one incoming missile...
PHRASAL VERB: V P n (not pron)
2.
If one person shoots down another, they shoot them with a gun.
He was prepared to suppress rebellion by shooting down protesters...
They shot him down in cold blood.
PHRASAL VERB: V P n (not pron), V n P
3.
If you shoot someone down or ~ their ideas, you say or show that they are completely wrong.
She was able to shoot the rumour down in flames with ample documentary evidence.
PHRASAL VERB: V n P, also V P n (not pron)