A cop or police officer. Is called so because his/her badge looks like it is made out of tin. A reference can be found in the movie "last action hero" with arnold scharzenegger
bad guy: "...who wants to know?"
arnold: ""the tin man ( holds up badge)"
badguy: " well, why dont you hit the bricks tin man"
arnold: " there not the right color"
An episode of Stargate SG1 in which the team's consciousnesses become duplicated and placed inside mechanized automaton versions of themselves by a man named Harland. The episode's title is one of Stargate's numerous references to The Wizard of Oz.
Can you believed the robot versions of the SG1 Team all stayed behind with Harland in Tin Man!?