'widening' originates from English, formed from the verb 'widen' + the nominal/gerund suffix '-ing'.

'widen' comes from Old English elements related to 'wīd' (meaning 'wide') with a verb-forming suffix (Old English 'wīdian'/'wīdian' → Middle English 'widen'), and the modern noun/gerund 'widening' developed from adding '-ing' to the verb.

Initially it meant 'to make wide' or 'to become wide'; over time it has kept that core sense and also broadened to mean increases in scope, range, or extent (e.g., widening gaps, widening participation).