Shoot up is a phrase that can be used to describe the act of rapidly increasing or rising, as well as the act of injecting drugs. The crossword solutions for this term are ROCKET (6 letters), SPROUT (6 letters), GROW (4 letters), SOAR (4 letters), SPIKE (5 letters), and INJECT (6 letters). ROCKET implies a sudden, powerful increase, while SPROUT suggests a gradual growth. GROW and SOAR both suggest an increase in size or altitude, respectively. SPIKE implies a sharp, sudden increase, and INJECT implies a forceful introduction of something.