Is the condition of a cat when it can't stop meowing for a period of time. The cause is unknown.
Damn dude, my cat has meowsis, she's been making noise all night.
by Oriental Ruppunzel September 04, 2009
1 more definition
The act of cats reproducing as in mitosis or meiosis with a few changes. During meowsis there is no telophase or anaphase.
My cats are performing the act of meowsis.
by fsu1000 April 19, 2011