Place one’s shirt at risk? (6)
I believe the answer is:
gamble
'risk?' is the definition.
(gamble is a kind of risk)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for gamble that I've seen before include "Wager; sounds like frolic" , "Take a chance, speculate" , "Take risks" , "Take a risk" , "Bet money" .)