1. (adverb)unawares without forethought or plan; inadvertently
"came upon the diamond unawares"
2. (adverb)unawares suddenly and unexpectedly
"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)short, unawares at a disadvantage "I was caught short"