headlong

The word 'headlong' is a native English compound formed from the Old English elements 'head' and 'long'. Originally, it was the phrase 'headling' (with the adverbial suffix '-ling'), meaning 'with the head foremost'. By the 14th century, it was influenced by and re-formed using the common adjective 'long', drawing on its now-archaic adverbial sense of 'lengthwise'. This combination literally paints the picture of the body being positioned 'head [first] and lengthwise'. Over time, the primary physical meaning of plunging with the head first naturally extended to describe any action undertaken with similar impulsive and reckless speed, prioritizing forward motion over caution.

Structure: head + long - head (Old English: hēafod): The upper part of the human body, containing the brain, eyes, and mouth. In this compound, it carries the literal sense of the physical head or the foremost part. - long (Old English: lang, long): Having great linear extent. In this compound, it functions in its obsolete adverbial sense meaning 'at full length' or 'along the length of'.