Definitions
1.NounA surprise attack or ambush; a sudden or unexpected assault. .mw-parser-output .defdate{font-size:smaller}
2.NounA sudden coming-upon someone or something unexpectedly or unawares.
3.NounA surprising event or occurrence.
4.NounThe feeling caused by being surprised; surprise, shock, amazement.
5.NounAn information measure as equal in bits (binary digits) to the base-2 log of 1 over the probability, with the result that the number of choices equals 2 where n is the number of bits.