Nouns

(n)tripper(slang) someone who has taken a psychedelic drug and is undergoing hallucinations
(n)stumbler, trippera walker or runner who trips and almost falls
(n)sightseer, excursionist, tripper, rubbernecka tourist who is visiting sights of interest
(n)tripper, tripa catch mechanism that acts as a switch“the pressure activates the tripper and releases the water”