nervous nellie

Short definition from Wiktionary

Noun

1. 1
   Alternative spelling of nervous Nellie.
2. 2
   Alternative spelling of nervous Nellie.
3. 3
   A person whose personality and behavior are characterized by worry, insecurity, and timidity.

Adjective

1. 1
   Alternative spelling of nervous-Nellie.
2. 2
   Alternative spelling of nervous-Nellie.
3. 3
   Characterized by worry or anxiety; having a weak, insecure personality.