Source:
Tesco Magazine, November/December 2006,pp.22

Original sentence:
"She was devastated when, in August 2005, she developed stress-related alopecia, a condition which caused her trademark long, blonde hair to fall out, leaving her completely bald in the space of just four weeks."

Definition:
adj.
feeling extremely shocked and sad

e.g.
She was left feeling totally devatated.

(Longman Dictionary of Contemporary English, New Edition, 2003)


Mnemonic:
First
-from the structure of the word
"de-vast-stated", "vast" means extremely large in size, amount, so just think about the state, the situation is extremely serious, which makes people extremely sad and surprised, that is-"devastated".

Second
-from the similar pronunciation in Chinese
"va"- reminds people the Chinese character "哇~",which people pronunce when they are crying sadly. So they state of pronuncing "哇~", which shows your upset feeling,is being "devastated".