The word "gratuitous" means something that is unnecessary or uncalled for. It often refers to something that is done or said without any reason or purpose. Full definition
The continuous analysis of programme content by communication researchers such as George Gerbner shows that the levels of gratuitous violence in U.S. television are as high as ever. (religion-online.org)
The action moves at fever pitch, with beautiful women, a really, really nasty villain, lots of medical lingo and liberal amounts of gratuitous violence from which our protagonist recovers with miraculous speed. (bookbrowse.com)
The Kyocera Hydro Vibe is a small and thick, by today's standards, with gratuitous use of hard plastic and a few different textures and finishes that try to make it look fancy but generally make it seem cheap. (androidcentral.com)