喧 is a bound form (b.f.) meaning 'loud and noisy' — it almost always appears as part of two-character words like 喧哗 (xuānhuá, 'to make noise'), 喧闹 (xuānnào, 'loud and bustling'), or 喧嚷 (xuānrǎng, 'to clamor'). You won't use it alone as a standalone word; it attaches to another character to form adjectives or verbs describing noise and commotion.