1) Ascend without walking 2) Carry up 3) Get out of control 4) Go up 5) Grow rapidly 6) Heat up 7) Increase 8) Increase a conflict 9) Increase in intensity 10) Increase rapidly 11) Increase rapidly in intensity 12) Intensify 13) Rise 14) Snowball 15) Step up 16) Swell 17) To intensify or step up 1) Climb 2) Increase 3) Intensify 4) Redouble 
to increase or make worse
[v] - increase in extent or intensity
escalate 1. To increase, to enlarge, or to intensify: 'The President was trying to escalate the number of troops in Iraq.' 2. To increase in intensity or extent: 'The democrats have had a deepening long-term impasse with President Bush that is certain to escalate.”
intensify 2 step up verb increase in extent or intensity; `The Allies escalated the bombing`
to increase in intensity, magnitude, etc.: to escalate a war; a time when prices escalate. · to raise, lower, rise, or descend on or as if on an escalator.
[Social studies terms] increase in extent or intensity increase in extent or intensity increase in extent or intensity