The phrase "great haste" means doing something very quickly or rushing to complete a task without wasting time.
Sentences with «great haste»
If I were a lady at Downton Abbey, my wishes would be obeyed with great haste. (rookiemoms.com)
Dear Jack McGlynn, I read your review in great haste last Wednesday. (filmireland.net)
However, it met with limited success as banks displayed great haste in hiking rates in a hardening interest rate scenario and reluctance in reducing them when the situation turned benign, disappointing borrowers. (yourloanadvisors.com)