'if-clause' originates from English, specifically from the conjunction 'if' (Old English 'gif') and the noun 'clause' (from Old French 'clause', from Latin 'clausula'), where 'gif' meant 'if/whether' and 'clausula' meant 'a closing'.

'if' changed from Old English word 'gif', and 'clause' changed from Latin 'clausula' via Old French 'clause'; these elements were combined in modern English grammatical terminology to form the compound 'if-clause'.

Initially, the components meant 'if/whether' (for 'if') and 'a closing' (for 'clause'), but over time the compound came to mean specifically 'a clause expressing a condition introduced by if'.