I will start with 2 words...next poster will carry on using the last word first, and so on....
(Remember... last word first!)
Example:
In crowd
Crowd control
Control freak
Ok, I'll start with -
Blue moon
Pond scum
Scum bag
Bag man
Man cave
Cave cricket
Cricket score
Score tied
Tied knot
Knot untangler
Untangler comb