(ن، ض) كَعَبَ يَكْعُبُ وَيَكْعِبُ كُعُوْبًاkaʿaba yakʿubu wa-yakʿibu kuʿūban: to swell, to protrude; also to be square (cubic). (This verb is not used in the Quran.)
كَعْبٌkaʿb pl. كِعَابٌkiʿāb, dual كَعْبَانِkaʿbāni (noun, ism dhāt): a protruding knob, such as the bone between the shin and the foot, i.e. the ankle. ﴿وَاَرْجُلَكُمْ اِلَي الْكَعْبَيْنِ﴾ (Al-Māʾidah 5:6)
كَعْبَةٌkaʿbah (noun, ism dhāt): a square, lofty building; «اَلْكَعْبَةُal-kaʿbat» the Kaʿbah. ﴿جَعَلَ اللّٰهُ الْكَعْبَةَ الْبَيْتَ الْحَرَامَ قِيٰمًا لِّلنَّاسِ﴾ (Al-Māʾidah 5:97)
كَاعِبٌkāʿib pl. كَوَاعِبُkawāʿibu (active participle, ism fāʿil): swelling, protruding; hence metaphorically for a young girl whose breasts have developed. Only once in the Quran: ﴿وَكَوَاعِبَ اَتْرَابًا﴾ (An-Nabaʾ 78:33)