DANGEROUSLY FAST, at full tilt, flat out, ventre à terre; informal hell for leather, like the wind, like a bat out of hell, like greased lightning; Brit. informal like the clappers.
2192; headword
AT BREAKNECK SPEED
Meaning of AT BREAKNECK SPEED in English
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012