'steadily-managed' originates from Modern English, specifically the adverb 'steadily' combined with the past participle 'managed'. 'steadily' is formed from the adjective 'steady' + the adverbial suffix '-ly', where 'steady' conveyed the sense of 'firm' or 'fixed'; 'manage' comes from Old French 'manegier' (or Italian 'maneggiare') ultimately related to Latin roots associated with 'manus' meaning 'hand'.

'steady' developed in English from words meaning 'firm' or 'fixed', and '-ly' created the adverb 'steadily'; 'manage' entered English via Old French/Italian from Late Latin terms connected to 'hand' and 'handling'. These elements were later combined in Modern English into the compound adjective 'steadily-managed' to describe something under steady handling.

Initially the components meant 'firm/fixed' (steady) and 'to handle or control' (manage); over time the combined expression came to mean 'kept under continuous, steady control' rather than referring to literal manual handling.