'sheikdom' originates from Arabic and Old English, specifically the Arabic word 'shaykh' (also spelled 'sheikh') meaning 'elder, leader' and the Old English element 'dōm' meaning 'judgment, state, condition' combined to form the modern English compound.

'shaykh' entered English (via Arabic 'shaykh'/'shaikh' and later spellings like 'sheikh') and combined with the Old English/Old Norse-derived suffix 'dom' (from Old English 'dōm') to yield 'sheikdom' (also seen as 'sheikhdom') in Modern English.

Initially, the elements referred separately to 'an elder/leader' and to 'a state/condition'; over time they fused into a compound meaning 'the territory or authority of a sheik,' which is the current sense.