Expressions (phrases, clauses, etc.), Godan verb with 'ku' ending
to catch fire; to be ignited; to ignite; to light (e.g. of a match)
摩擦でマッチに火がつくようになる。Friction causes a match to light. to flare up (of an emotion, controversy, etc.); to blaze; to be ignited (of a dispute, commotion, etc.); to take off (of a boom, craze, etc.)
Idiomatic expression
Also written 火が付く【ひがつく】、火が点く【ひがつく】