Related Clues:

• Underlying structure
• Unit of play in snooker tournament
• Surrounding structure
• There's not a billy goat in there, there's a picture
• Catch a bit back at the end
• That's the way to catch up with most of your partner
• Catch most of the partner 8 across?
• There's something about a picture with a pump inside
• The catch in this is that it's up to almost all one's mate
• In this you get the picture of the sheep inside
• The way to catch the headless fowl up a bit
• If the hen has lost her head, you can catch only a bit of her back there
• Catch this on H for the makings of 27 across
• Catch a bit of a bit up
• The catch is that it's a bit of a hen and another bit too