18-letter words containing h, i, p, o, d, a
- pyromucic aldehyde — furfural.
- pyrosulphuric acid — a fuming liquid acid made by adding sulphur trioxide to concentrated sulphuric acid. Formula: H2S2O7
- rhodes scholarship — one of a number of scholarships at Oxford University, established by the will of Cecil Rhodes, for selected students (Rhodes scholars) from the British Commonwealth and the United States.
- scholarship holder — a person who, because of academic merit, receives financial aid for their studies
- secondary syphilis — the second stage of syphilis, characterized by eruptions of the skin and mucous membrane.
- september holidays — a period of time in September when people do not have to go to school, college or work
- southampton island — an island in N Canada, in the Northwest Territories at the entrance to Hudson Bay. 19,100 sq. mi. (49,470 sq. km).
- the operative word — If you describe a word as the operative word, you want to draw attention to it because you think it is important or exactly true in a particular situation.
- thiosulphuric acid — an unstable acid known only in solutions and in the form of its salts. Formula: H2S2O3
- to pick and choose — If you pick and choose, you carefully choose only things that you really want and reject the others.
- triphosphoric acid — the hypothetical acid H 5 P 3 O 10 , known chiefly by its salts.
- vectorcardiography — a method of determining the direction and magnitude of the electrical forces of the heart.
- white-spotted hyla — a type of tree frog (H. leucophyllata) of tropical America
- withdrawal symptom — effects of stopping a drug
- world championship — an international competition in a particular sport or activity for people all around the world