a. A knob, knot, protuberance, or swelling.
b. Medicine A small, well-defined mass of tissue that is either normal or pathological, as a lymph node or a node at an arthritic joint.
a. A point or area where two lines, paths, or parts intersect or branch off: "The nodes, or branching points, are usually demarcated by sets of one or more new, evolutionary characters that typify all taxa" (Pat Shipley).
b. A focal point or a point of interaction: "Inside the hospital, she became a node of gossip, despite being unable to communicate in the usual way" (Oliver Sacks).
a. Botany The point on a stem where a leaf is attached or has been attached; a joint.
b. See knot1.
4. Physics A point or region of virtually zero amplitude in a wave or periodic system.
5. Mathematics The point at which a continuous curve crosses itself.
6. Computers A terminal in a computer network.
a. Either of two diametrically opposite points at which the orbit of a planet intersects the ecliptic.
b. Either of two points at which the orbit of a satellite intersects the orbital plane of a planet.
[Middle English, lump in the flesh, from Latin nōdus, knot; see ned- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2017 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.
American Heritage Dictionary Products
The American Heritage Dictionary, 5th Edition
The American Heritage Dictionary of Idioms
The American Heritage Roget's Thesaurus
Curious George's Dictionary
The American Heritage Children's Dictionary
The American Heritage Dictionary of Indo-European Roots
The American Heritage Student Grammar Dictionary
The American Heritage Desk Dictionary + Thesaurus
The American Heritage Science Dictionary
The American Heritage Dictionary of Business Terms
The American Heritage Student Dictionary
The American Heritage Essential Student Thesaurus