Related Clues:

• Cause to increase, say dispute (8).
• Increase in intensity or extent
• Sudden upward movement
• Raise to higher level, perhaps war
• Increase in intensity or extent, like trouble brewing
• Move rapidly forward like a wave
• Increase in extent or intensity
• Increase in extent or intensity (8)V
• Sudden rapid rise
• Move forward like wave
• If the case were to get confused and get behind time it would get worse
• The broken case, being no more, will get more so
• For the case to get broken and get dead makes it get more so
• Has the South got an impulse to wave?
• Sounds like material for a swell