Irrelevant is an adjective which means something which is not significant or unimportant.

Sentences:

1. The questions asked were irrelevant to our syllabus.

2. The arguments made by the lawyer were irrelevant to the case,

Irreverent is an adjective used to define a person who doesn’t respect things, which are generally taken seriously.

Sentences:

1. Criminal minds are known for irreverence for the laws.

2. The news report was irreverent towards the Prime Minister