Cat communication: The meaning of meow

Murmur: Rhythmically pulsed vocalization; exhalation, social interactions, solicitation, non threatening, possibly related to dyssynchronous contraction of muscles in larynx and diaphragm (Remmers & Gautier 1972)
Growl: Low-pitched, harsh; lengthy, agonistic (Bushnell 1963)
Squeak: High-pitched, raspy, associated with anticipation of feeding; given by females after copulation
Shriek: Loud, high-pitched; pain, fear, aggression
Hiss: Agonistic, mouth open, teeth visible; offensively defensive (avoids frank aggression)
Spit: Short sound before or after hiss
Chatter: Anticipation, frustration
Purr: Contentment, nursing, mild conflicting anxiety
Chirr: Queen's call to kittens
Mew: High-pitched, medium amplitude; mother-kitten interaction for location, identification, encouragement
Moan: Low frequency, long duration; epimelectic; regurgitation, solicitation
Meow: Greeting, epimelectic, willingness to interact
Data from Moelk (1944) and McKinley (1982)