tightening (n.)

• accelerando
• acceleration
• aggravation
• blowup
• compression
• concentration
• condensation
• consolidation
• crescent
• crush
• deepening
• enhancement
• exacerbation
• exaggeration
• explosion
• growing
• intensification
• lengthening
• magnification
• nip
• pickup
• pinch
• press
• pressure
• reinforcement
• speedup
• spreading
• squeeze
• squeezing
• step-up
• strengthening
• swelling
• tweak
• waxing