1. a reversal of progress; a setback or check in forward movement
Usage: somewhat formal or literary
2. a current or flow of water or air moving backward
Usage: technical; nautical or meteorological

Examples

• The project suffered a major backset when the funding fell through.
• Despite the backset, the team remained committed to their goals.
• Economic growth experienced a temporary backset during the recession.
• The backset in negotiations delayed the agreement by several months.
• A backset in her recovery meant she had to extend her rehabilitation period.