'broad-striped' is a compound formed from 'broad' and 'striped'. 'broad' originates from Old English 'brād' (from Proto-Germanic *braidaz), where the root meant 'wide'. 'striped' derives from Middle English 'stripe' (likely from Old Norse 'stripa'), where the original sense was 'a strip, band, or streak'.

'broad' changed from Old English 'brād' into the modern English 'broad'. 'stripe' developed in Middle English as 'stripe' (influenced by Old Norse 'stripa') and later produced the adjectival form 'striped'; combined, they formed the compound adjective 'broad-striped' in Modern English.

Initially the components referred to 'wide' and 'a band/streak' respectively; over time the compound came to mean specifically 'having wide stripes' with little change in basic sense.