Related Clues:

• Surround, with 'on'
• Encircle
• Draw near
• Pen up
• Tighten the circle
• Prepare to raid
• Narrow the gap
• Converge on
• (Of days) grow shorter
• Shorten line so variable beneath constant
• Operating at a small distance
• (Of days) get successively shorter
• Silly to draw net tighter
• Approach, as to attack
• Get nearer