'unempirical' originates from English, formed by combining the prefix 'un-' (from Old English 'un-', meaning 'not') with 'empirical', which itself ultimately comes from Greek 'empeirikos' via Latin/Medieval Latin.

'empirical' came into English via Medieval Latin/Old French from Greek 'empeirikos' (from 'empeiria' meaning 'experience'); 'unempirical' is a modern English formation created by prefixing 'un-' to 'empirical'.

Initially the roots referred to 'experience' (Greek 'empeiria'); over time 'empirical' meant 'based on observation or experience,' and 'unempirical' evolved to mean 'not based on observation or experiment' (i.e., lacking empirical evidence).