'high-necked' originates from English, specifically as a compound of the words 'high' + 'neck' with the adjectival suffix '-ed', where 'high' meant 'elevated' and 'neck' meant 'the neck or neckline'.

'high' comes from Old English 'hēah' (later Middle English 'high'); 'neck' comes from Old English 'hnecca' (later Middle English 'neck(e)'); the suffix '-ed' (adjectival/past-participial) was attached in Modern English to form the compound adjective 'high-necked'.

Initially a straightforward compound meaning 'having a high or elevated neck/neckline'; this basic descriptive sense has been retained into modern usage meaning 'having a high neckline'.