1) His underhandedness was revealed when his scheme to sabotage the project came to light.

2) She resorted to underhandedness to win the competition.

3) The politician's reputation was tarnished by his underhandedness in the election.

4) The team suspected underhandedness from their opponent's unexpected victory.

5) Her underhandedness was evident in the way she stole credit for her colleague's work.

6) The underhandedness of the business deal became apparent during the investigation.

7) He showed his underhandedness by spreading false rumors about his rival.

8) The company's downfall was attributed to the CEO's underhandedness in handling finances.

9) The coach's underhandedness in manipulating game outcomes was eventually exposed.

10) The movie villain's underhandedness made him an unforgettable character.