The action or process of detraining; getting off or unloading from a train.
From detrain + -ment (noun suffix that creates abstract nouns from verbs). A formal, technical term more common in military and railroad documentation than everyday speech.
Detrainment is the kind of word that appears in official military orders and railroad schedules, not in casual conversation—it's part of the specialized vocabulary that different professions use to communicate precisely with each other.
Complete word intelligence in one call. Free tier — 50 lookups/day.