1. To die or be destroyed, especially in a violent or untimely manner: Must then a Christ perish in torment in every age to save those who have no imagination?(George Bernard Shaw).
2. To pass from existence; disappear gradually: Man will go down into the pit, and all his thoughts will perish(A.J. Balfour).
3. Chiefly British To spoil or deteriorate.
v.tr.
To bring to destruction; destroy: Many foul blights/Perishd his hard won gains(Thomas Hood).
Idiom:
perish the thought
Used to express the wish that one not even think about something.
[Middle English perishen, from Old French perir, periss-, to perish, from Latin perre : per-, per- + re, to go; see ei- in Indo-European roots.]
perish /pr/ v.frml. [I] -ishes to die, be killed in a sudden or dramatic manner: He fell from the ship and perished in the ocean.
p
r
/ v.frml. [I] -ishes to die, be killed in a sudden or dramatic manner: He fell from the ship and perished in the ocean. 
r
sh)
re : per-, per- +