attrition(loss of participants during an experiment) noun [UK: ə.ˈtrɪʃ.n̩] [US: ə.ˈtrɪʃ.n̩]
desertion [desertions](deserting) noun [UK: dɪ.ˈzɜːʃ.n̩] [US: dɪˈ.ˈzɝː.ʃn̩]Desertion from the army was grounds for the death penalty. = La deserción desde el ejército era motivo para la pena de muerte.