event vs placebo effect

event and placebo effect both are nouns.

Word	Noun	Adjective	Verb	Adverb
event	Yes	No	No	No
placebo effect	Yes	No	No	No

As nouns, placebo effect is a hyponym of event; that is, placebo effect is a word with a more specific, narrower meaning than event:

event: a phenomenon that follows and is caused by some previous phenomenon
placebo effect: any effect that seems to be a consequence of administering a placebo; the change is usually beneficial and is assumed result from the person's faith in the treatment or preconceptions about what the experimental drug was supposed to do; pharmacologists were the first to talk about placebo effects but now the idea has been generalized to many situations having nothing to do with drugs

event (noun)	placebo effect (noun)
something that happens at a given place and time	any effect that seems to be a consequence of administering a placebo; the change is usually beneficial and is assumed result from the person's faith in the treatment or preconceptions about what the experimental drug was supposed to do; pharmacologists were the first to talk about placebo effects but now the idea has been generalized to many situations having nothing to do with drugs
a phenomenon located at a single point in space-time; the fundamental observational entity in relativity theory
a phenomenon that follows and is caused by some previous phenomenon
a special set of circumstances