unawares
1. [ adverb ] without forethought or plan; inadvertently
Examples:

"came upon the diamond unawares"

2. [ adverb ] suddenly and unexpectedly
Examples:

"rain caught them unawares" "sorrow comes to all, and to the young it comes with bittered agony because it takes them unawares"- A.Lincoln

3. [ adverb ] at a disadvantage
Synonyms: short
Examples:

"I was caught short"

Similar spelling:   unrest
  unrested
  unrestored
  unresolved
  unreserved
  unworkable
  unrestraint
  unrespected
  unresisting
  unresistant
  unresentful