Relevant means connected to what is being discussed, and connected in a way that matters. The relevant page of the contract, the relevant experience on your CV, a question that is actually relevant to the lesson rather than to lunch.
It nearly always takes to: relevant to the case, relevant to my situation, relevant to nobody in this room. The noun is relevance, and the opposite, irrelevant, is what people reach for when they want to shut a comment down. Relevant also means still worth listening to now — a forty-year-old book that is still relevant, a band fighting to stay relevant. Careful, though: relevant is not a synonym for important. A fact can be true, important and completely irrelevant to the argument in front of you.
1adjectiverelevantConnected with what is being discussed, and important to it.
“Please bring any relevant documents to the meeting.”
synonyms: pertinent, applicable
2adjectiveparticularConnected with a particular person or situation.
“The new rules are not relevant to part-time staff.”
3adjectiveusefulStill important or useful today.
“The play is a hundred years old and still relevant.”
Relevant started as Scots legal jargon in the early 1500s, where it meant 'legally pertinent', and only crossed into general English in the 1700s. It borrows Latin relevāns, from relevō — re-, 'again', plus levō, 'lift'. A relevant point lifts the case; an irrelevant one leaves it lying where it was.
Latin
relevāns
Scots
relevant
English, today
relevant
Built from
From Scots relevant meaning "legally pertinent," used in Scottish legal circles starting in the early 1500s, and first used in English in the 1700s. Borrowed from Latin relevāns, present active participle of relevō (“lift up again, lighten, relieve”), from re- (“again”) + levō (“lift”).
Etymology from Wiktionary, CC BY-SA