'shabbily-built' originates from English, specifically the adverb 'shabbily' (formed from the adjective 'shabby' + suffix '-ly') and the past participle 'built' of the verb 'build'.

'shabbily' developed from 'shabby' + '-ly' (Middle English/early modern formation), while 'build' comes from Old English (e.g. 'byldan' / 'buildan') through Middle English 'bilden' to modern English 'build' and its past participle 'built'.

Initially, 'shabby' referred to being tattered, worn, or scabby; over time it broadened to describe things that are in poor condition or of inferior quality. The verb 'build' has retained the core meaning 'to construct'.