Definition of metaphasis:
(n) :
The accidental transposition of part of the sounds of two words in a phrase; the production of spoonerisms.
(n) :
(biology) Alternative form of metaphase. [(biology) The stage of mitosis and meiosis that follows prophase and comes before anaphase, during which condensed chromosomes become aligned before being separated.]
(n) :
(biology) Alternative form of metaphysis. [(anatomy, countable) The part of a long bone that grows during development]