Definition of buzz:
(n) :
a continuous, humming noise, as of
bees; a confused murmur, as of general conversation in low tones, or of a general expression of surprise or approbation; a whisper; a report spread secretly or cautiously
"still feeling the buzz from the coffee, he pushed through the last of the homework."
(v) :
to make a low, continuous, humming or sibilant sound, like that made by bees with their wings. Hence: To utter a murmuring sound; to speak with a low, humming voice; to sound forth by buzzing