18-letter words containing h, a, p, y, g
- spherical geometry — the branch of geometry that deals with figures on spherical surfaces.
- sympathetic string — a thin wire string, as in various obsolete musical instruments, designed to vibrate sympathetically with the bowed or plucked strings to reinforce the sound.
- vectorcardiography — a method of determining the direction and magnitude of the electrical forces of the heart.
- whispering gallery — a space or gallery beneath a dome or broad arch in which low sounds produced at any of certain points are clearly audible at certain other distant points.