'wide-reaching' is formed from the adjective 'wide' and the present participle 'reaching'. 'wide' originates from Old English 'wīd' (from Proto-Germanic *wīdaz) meaning 'broad' or 'extensive', and 'reach' originates from Old English 'rǣcan' meaning 'to reach' or 'to come to'.

'wide' developed from Old English 'wīd' into Middle English 'wide' and then modern English 'wide'; 'reach' developed from Old English 'rǣcan' into Middle English 'rechen/rechen' and eventually modern English 'reach'. The compound adjective 'wide-reaching' arose by combining the adjective and the participle to describe something that 'reaches widely'.

Initially each element meant 'broad' ('wide') and 'to extend or attain' ('reach'); over time the compound came to mean 'having a broad scope or influence' rather than a literal act of reaching.