'ruleless' originates from Modern English, formed by combining the noun 'rule' (from Old French 'reule', ultimately from Latin 'regula', meaning 'a straight stick, a rule or principle') and the suffix '-less' (from Old English 'lēas', meaning 'without').

'rule' developed from Old French 'reule' into Middle English 'rule' and then modern English 'rule'. The suffix '-less' comes from Old English 'lēas', became Middle English '-les', and later the Modern English suffix '-less'; together they produced the adjective 'ruleless' in Modern English.

Initially it literally meant 'without rule' (i.e., lacking a rule) and over time it retained and generalized to the current meaning 'not governed by rules; lacking regulation'.