Green’s Dictionary of Slang

1. (orig. US) a show of personal power, esp. if blatant.

1971		J. Mandelkau Buttons 85: He was on his own power trip.
1977		C. McFadden Serial 21: Screaming at Harvey about how he was a ‘sickie on a power trip’.
1989		T. Blacker Fixx 306: No power trips, just a basic understanding between us that we all do it his way.
1996		P. Cornwell Cause of Death (1997) 259: ‘Why might someone be doing this?’ I asked [...] ‘A power trip, no pun intended,’ Janet simply said.
2004		P. Howard PS, I Scored the Bridesmaids 80: Those poor people, I made their lives miserable [...] I was on some power trip.

2. attrib. use of sense 1.

1993

A. Rodriguez Spidertown (1994) 102: Maybe she wanted to make a little power-trip display — she was with these three gorillas [...] arms down to their ankles, eyes born glaring.