An idiom is an expression whose meaning is not readily apparent based on the individual words in the expression. This forum is dedicated to discussing idioms and other sayings.
A (de carne) grinding (inglés norteamericano), mincing (inglés británico); (de cebolla, ajo) chopping
B (España) (descenso pronunciado): el avión cayó en picado the plane nose-dived; el pájaro cayó en picado al agua the bird plunged o dived into the water; las acciones descendieron en picado stocks plummeted o plunged
Plunge is fine, but "caer en picada" (as we say around here) doesn't necessarily anticipate the "landing"... it is commonly used to say something (a plane, a bird, stocks, prices...) falls vertically and fast (like "free falling", I guess).
__________________ ♪ ♫ ♪ Ain't it wonderful to be alive when the Rock'n'Roll plays... ♪ ♫ ♪