Related Clues:

• Glue, perhaps, joining two animals?
• Marine worker enclosing large water barrier?
• Prop for a tilting bookcase, say
• Material to make watertight
• Constituency must keep network impenetrable with this preparation
• Man investing in firm substance for stopping leaks
• Directed to cover aluminium with a protective substance
• Pair of creatures, big and small, that makes a bond
• It'll fill a hole
• Bond formed by boy in group