• 鏡かがみ — mirror
• 鏡台きょうだい — dressing table
• 眼鏡めがね — glasses (spectacles)
• 水鏡すいきょう — water reflection
• 銅鏡どうきょう — bronze mirror
• 破鏡はきょう — broken mirror

The kanji 鏡 is a phono-semantic compound: it combines 金 (metal) with the phonetic 京. It originally referred to metal mirrors, which were polished to a reflective surface. Today it also conveys metaphorical ideas, like reflecting one’s true self or social ideals.

鏡かがみを 見みて、髪かみを 整ととのえます。
I check the mirror and fix my hair.

彼女かのじょは 鏡かがみの 前まえで 立たち 止どまりました。
She stopped in front of the mirror.

🎧 The on-yomi キョウ appears in compound words like 鏡台 and 銅鏡. The kun-yomi かがみ is used when the kanji stands alone, such as in 鏡 (mirror).