The Collaborative International Dictionary of English v.0.48:

fizz \fizz\ (f[i^]z), v. i. [imp. & p. p. fizzed (f[i^]zd); p.
   pr. & vb. n. fizzing.] [Cf. Icel. f[imac]sa to break wind,
   Dan. fise to foist, fizzle, OSw. fisa, G. fisten, feisten.
   Cf. Foist.]
   To make a hissing sound, such as that of a burning fuse or a
   bubbling carbonated beverage.
   [1913 Webster +PJC]

The Collaborative International Dictionary of English v.0.48:

fizzing \fizzing\ fizzy \fizzy\adj.
   Hissing and bubbling, like a carbonated beverage.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

fizzing
    adj 1: hissing and bubbling [syn: fizzing, fizzy]