| BUTTERHORNS | • butterhorns n. Plural of butterhorn. |
| HEARTSTRING | • heartstring n. Singular of heartstrings. • HEARTSTRING n. a nerve or tendon imagined to brace and sustain the heart; (in plural) affections. |
| INTERGROWTH | • intergrowth n. A growing together and through each other of two crystals. • INTERGROWTH n. a growing between or together. |
| NORTHEASTER | • northeaster n. An extratropical storm, usually found in coastal New England and Atlantic Canada, whose winds usually… • NORTHEASTER n. a strong northeast wind. |
| NORTHERMOST | • northermost adj. Synonym of northernmost. • NORTHERMOST adj. most northerly, also NORTHERNMOST, NORTHMOST. |
| NORTHWESTER | • northwester n. A strong wind blowing from the northwest. • NORTHWESTER n. a strong northwest wind. |
| ORNITHOPTER | • ornithopter n. An aircraft that generates lift through the flapping of its wings. • ORNITHOPTER n. a birdlike archaic flying machine. |
| ORTHOCENTER | • orthocenter n. (Geometry) The intersection of the three lines that can be drawn flowing from the three corners of a… • ORTHOCENTER n. the point of intersection of the altitudes of a triangle, also ORTHOCENTRE. |
| ORTHOCENTRE | • orthocentre n. Alternative form of orthocenter. • ORTHOCENTRE n. the point of intersection of the altitudes of a triangle, also ORTHOCENTER. |
| ORTHOPTERAN | • orthopteran n. (Zoology) Any of many insects of the order Orthoptera. • ORTHOPTERAN n. any member of the Orthoptera, an order of mandibulate insects, also ORTHOPTERON. |
| ORTHOPTERON | • orthopteron n. Alternative form of orthopteran. • ORTHOPTERON n. any member of the Orthoptera, an order of mandibulate insects, also ORTHOPTERAN. |
| RINTHEREOUT | • RINTHEREOUT n. (Scots) a vagrant. |
| TETRAHEDRON | • tetrahedron n. (Geometry) A polyhedron with four faces; the regular tetrahedron, the faces of which are equal equilateral… • TETRAHEDRON n. a polyhedron that has four faces. |
| THREATENERS | • threateners n. Plural of threatener. • THREATENER n. one who threatens. |
| TROCHANTERS | • trochanters n. Plural of trochanter. • TROCHANTER n. a rough eminence on the thigh bone to which muscles are attached. |
| UNDERTHIRST | • UNDERTHIRST n. (Wordsworth) an underlying or subconscious thirst. |
| UNDERTHRUST | • underthrust v. (Geology, of a tectonic plate) To thrust under another. • UNDERTHRUST v. to insert (a faulted rock mass) into position under a passive rock mass. |
| UNTHRIFTIER | • unthriftier adj. Comparative form of unthrifty: more unthrifty. • UNTHRIFTY adj. not thrifty. |