imitate vs pattern

imitate is not a noun while pattern is a noun.

Word	Noun	Adjective	Verb	Adverb
imitate	No	No	Yes	No
pattern	Yes	No	Yes	No

As verbs, pattern is a hyponym of imitate; that is, pattern is a word with a more specific, narrower meaning than imitate:

Other hyponyms of imitate include conform to, follow, mock, take off, mime, mimic, model, follow, take after, emulate.

imitate (noun)	pattern (noun)
	a customary way of operation or behavior
	a decorative or artistic work
	a perceptual structure
	a model considered worthy of imitation
	something intended as a guide for making something else
	something regarded as a normative example
	graphical representation (in polar or Cartesian coordinates) of the spatial distribution of radiation from an antenna as a function of angle
	the path that is prescribed for an airplane that is preparing to land at an airport

imitate (verb)	pattern (verb)
reproduce someone's behavior or looks	plan or create according to a model or models
make a reproduction or copy of	form a pattern
appear like, as in behavior or appearance