'unreliably-supported' originates from the combination of 'unreliable' and 'supported'. 'Unreliable' comes from the prefix 'un-' meaning 'not' and 'reliable' from Latin 'reliabilis', meaning 'that may be relied on'. 'Supported' comes from Latin 'supportare', meaning 'to carry' or 'to bear'.

'Unreliable' evolved from Middle English 'unrelyable', and 'supported' from Old French 'supporter', eventually forming the modern English term 'unreliably-supported'.

Initially, 'unreliable' meant 'not to be depended on', and 'supported' meant 'to bear or hold up'. Together, they evolved to describe something not consistently backed by evidence.