'shadblow' originates from English, specifically a compound of the words 'shad' and 'blow', where 'shad' referred to the fish and 'blow' meant 'bloom' or 'blossom'.

'shadblow' developed as a regional compound in North America, used alongside forms such as 'shadbush' and 'shad-bloom' in dialectal speech from the 18th–19th centuries and stabilized as the recorded form 'shadblow' in later usage.

Initially it meant 'the bloom of the shadbush', but over time it also came to be used for the shrub or small tree that bears those blooms.