'crossbeam' originates from Middle English, specifically the words 'cros' and 'beme', where 'cros' meant 'cross' and 'beme' meant 'beam'.

'cros' and 'beme' combined in Middle English to form 'crossbeam', which has remained largely unchanged in modern English.

Initially, it meant 'a beam that crosses', and this meaning has largely remained the same in modern usage.