act vs portray

act is a noun but portray is not a noun.

Word	Noun	Adjective	Verb	Adverb
act	Yes	No	Yes	No
portray	No	No	Yes	No

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

Other hyponyms of act include make, make believe, pretend, support, act out, enact, reenact, act out, impersonate, parody, emote.

act (noun)	portray (noun)
something that people do or cause to happen
a subdivision of a play or opera or ballet
a legal document codifying the result of deliberations of a committee or society or legislative body
a short performance that is part of a longer program
a manifestation of insincerity

act (verb)	portray (verb)
behave in a certain manner; show a certain behavior; conduct or comport oneself	portray in words
pretend to have certain qualities or state of mind	make a portrait of
discharge one's duties	assume or act the character of
play a role or part	represent abstractly, for example in a painting, drawing, or sculpture
perform on a stage or theater
behave unnaturally or affectedly
perform an action, or work out or perform (an action)
have an effect or outcome; often the one desired or expected
be suitable for theatrical performance