breakneck

[ breyk-nek ]

/ ˈbreɪkˌnɛk /

reckless or dangerous, especially because of excessive speed; hazardous: He raced through the streets at breakneck speed.

Origin of breakneck

First recorded in 1555–65; break + neck

Best Buy is caught up in the breakneck world of technological innovation.

Best Buy Punches Back at Amazon |William O’Connor |December 27, 2014 |DAILY BEAST
Private parts, be they of ducks, damselflies or dung beetles, turn out to have evolved novel forms at breakneck speeds.

Oh, if These Penises and Vaginas Could Talk: Genitalia as Tools, Toys, and Weapons |Menno Schilthuizen |May 1, 2014 |DAILY BEAST
Then try to get a ticket for a Maple Leafs match, to watch the breakneck brutality in action.

Where to Win Your Own Winter Olympics |Lonely Planet |January 4, 2014 |DAILY BEAST
To maintain its breakneck growth, it almost has to look for younger members.

LinkedIn and the Internet’s New Organization Kids |Daniel Gross |August 21, 2013 |DAILY BEAST

For one breakneck moment Monday, she looked dead ahead and saw her husband surfing toward her, and then down toward the rocks.

Surfer Garrett McNamara May Have Conquered His 100-Foot Wave |Andy Jacobsohn |January 31, 2013 |DAILY BEAST
Four of the Germans got away and raced across country at breakneck speed.

The Post of Honour |Richard Wilson
Now a steep hill loomed up in front of him, and he rushed it at breakneck speed.

Bert Wilson's Twin Cylinder Racer |J. W. Duffield
She kept the breakneck pace till she pulled up at the court entrance.

The Trail of Conflict |Emilie Baker Loring
Fronklyn placed himself at the head of his men, with Deck near him, and they dashed into the pass at a breakneck speed.

In The Saddle |Oliver Optic
And so the men set out at breakneck speed, as if they were in a hundred yard's dash.

A Prisoner of Morro |Upton Sinclair

breakneck

/ (ˈbreɪkˌnɛk) /

(prenominal) (of speed, pace, etc) excessive and dangerous