'non-climbing' originates from Modern English, specifically combining the prefix 'non-' (from Old French and ultimately Latin 'non'), where 'non' meant 'not', and the present participle 'climbing' from the verb 'climb'.

'climb' changed from Old English word 'climban' and Middle English 'climben' and eventually became the modern English verb 'climb', which forms the participle 'climbing'; the negative prefix 'non-' was borrowed into English via Old French from Latin 'non'.

Initially, the compound simply meant 'not climbing' and this core meaning has been retained in modern usage.