Definition from Wiktionary, the free dictionary
- (cycling) An unpaced race in which riders or teams, leaving at regular intervals are timed over a preset course or distance, the winner being the rider or team to finish in the fastest time.
- Any competitive event in which competitors are timed rather than racing against each other.
- (in cycling): race of truth
Derived terms 
- individual time trial
- team time trial
- time trial bicycle
- time-trialing, time-trialling
- time trialist, time triallist
race in cycling
competitive event in which competitors are timed rather than racing against each other