noun

a rapid increase; a rise.

cost escalations

rapid increase,rise,hike,advance,growth,leap,upsurge,upturn,upswing,climb,jump,spiralling,intensification,aggravation,exacerbation,compounding,increase,enlargement,magnification,mushrooming,amplification,augmentation,expansion,stepping-up,build-up,buildout,heightening,widening,worsening,deterioration