'uncaptioned' originates from English, specifically formed by adding the prefix 'un-' to the word 'caption', where 'un-' meant 'not' and 'caption' meant 'a brief description or title'.

'caption' entered English from Old French and Medieval Latin usages of a word related to Latin roots meaning 'head' or 'title'; the adjective 'uncaptioned' is a modern English formation by negative prefixation ('un-' + 'caption' + '-ed').

Initially 'caption' referred to a heading or short explanatory text; the formation 'uncaptioned' came to mean 'not having such a heading or explanatory text'.