Entomology

Das Stigma looks like a word English readers already own, and in this list it means something they would not guess: a spiracle, one of the small openings along an insect’s body through which air reaches die Tracheen. What trips people up is the plural. German keeps two, and each belongs to its own world. In a biology text the spiracles are die Stigmen, on the pattern of das Thema and die Themen. Die Stigmata is the plural you meet in church history, for the wounds of Christ or of Francis of Assisi. Write die Stigmata in a paper on how beetles breathe and the sentence is still grammatical, but it sounds as if it had wandered in from a sermon. The singular is the same in both worlds, so it is the plural that tells a reader which one a text belongs to.