Endocrinology

Le titre des anticorps is the antibody titre, and the French word inside it does more work than its English lookalike. « Title » in English names things: a book, a rank, a claim to a piece of land. Le titre does all of that as well — le titre du roman, à quel titre parlez-vous, les titres du journal for the headlines, un titre de transport for a bus ticket, les titres for shares and bonds. But it carries a second family that English keeps in separate words: how much of one thing is sitting inside another. Le titre alcoométrique is the strength of a drink, le titre d’une solution its concentration, and le titre des anticorps how much antibody the blood is holding. The verb runs in both directions at once: titrer une solution is to measure that strength, while le journal titre sur la crise means the paper leads with it. English did take the second family, spelling and all, which is why a laboratory writes « titre » and never « title » — but it left the first one behind, so on this side the two never meet.