'improperly-managed' is a compound word formed from 'improperly' (from 'improper' + '-ly') and 'managed' (past participle of 'manage'). 'Improper' comes from Latin 'improprius' meaning 'not proper', and 'manage' comes from Italian 'maneggiare' meaning 'to handle'.

'improperly' and 'managed' were combined in modern English to form the compound adjective 'improperly-managed'.

Initially, 'improperly-managed' simply described something not managed properly, and this meaning has remained consistent.