collar up

Verb

 * 1)  To apply a harness to a horse.
 * 2)  To put a collar on a dog (a band or chain around an animal's neck).
 * 3)  To build up a lip or collar around a hole.
 * 4)  To raise the collar on a shirt or jacket (the part of an upper garment (shirt, jacket, etc.) that fits around the neck and throat).
 * 5)  To engage in a collar trade (taking equal but opposite positions in a put and a call with different strike prices).
 * 6)  To arrest (someone); to arrest one or more people.