"Relevant" is an adjective that describes something that is
closely connected to a subject being discussed, researched or
investigated. An example sentence: "Her testimony was relevant to
the court case." "Irrelevant" is an adjective and antonym of
"relevant. It means that something is not connected or not
connected to a particular subject. An example sentence: "His
comment on the circus was irrelevant to our discussion on
basketball."