ش ی خsh-y-kh
(ض) شَاخَ يَشِيْخُ شَيْخًا وَشَيْخُوْخَةًshākha yashīkhu shaykhan wa-shaykhūkhatan: (1) to grow old (2) to be great in knowledge, excellence or rank (the word is not used in this sense in the Quran).
شَيْخٌshaykh pl. شُيُوْخٌshuyūkh (also an adjective): old man. ﴿وَّهٰذَا بَعْلِيْ شَيْخًا﴾ (Hūd 11:72); ﴿وَاَبُوْنَا شَيْخٌ كَبِيْرٌ﴾ (Al-Qaṣaṣ 28:23); ﴿ثُمَّ لِتَكُوْنُوْا شُيُوْخًا﴾ (Ghāfir 40:67)