pafmortigi

Decode it and there is no mystery. Pafi at rank 885 is to shoot, mortigi at 281 is to kill, and the two verbs are simply welded together. Esperanto builds this kind of compound freely: the first root says by what means, the second says what happened. Pafmortigi is to kill, and the shooting is the method.

Why the course now has two words for this.Mortpafi arrived at rank 2,525 and looks like the same word with the halves swapped, because it nearly is. The difference is which root is the head. Mortpafi is a kind of shooting: you shoot, fatally. Pafmortigi is a kind of killing: you kill, by shooting. In practice the two are used interchangeably in reporting and history writing, and no reader will misunderstand either. If you want a rule of thumb, mortpafi reads slightly more like a headline and pafmortigi slightly more like a legal or historical record.

Register, plainly. This is a word for wars, revolutions and history books. The whole family it belongs to sits in that register: murdi at 1,092 for murder, ekzekuti at 2,055 for a judicial execution, soldato at 661 and armilo at 1,126 for the people and the tools. You need the word to read a history of the twentieth century in Esperanto. You will not need it in conversation, and that is the correct proportion.