sometimes called a “relative majority” in British English
Which has been simplified to just majority in the normal parlance in political coverage in the UK (see BBC, Sky News etc. in their coverage, they all use majority to mean relative majority when reporting on GE election results)
According to that same Wikipedia link you shared:
Which has been simplified to just majority in the normal parlance in political coverage in the UK (see BBC, Sky News etc. in their coverage, they all use majority to mean relative majority when reporting on GE election results)