Return to the home page.

Expand/collapse menu.

Visit Our Sites

Unabridged Dictionary

Learner's Dictionary

Word Central for Kids

Expand/collapse menu.

Premium Services

Unabridged Dictionary

Encyclopedia Britannica

Institutional Subscriptions

Expand/collapse menu.

Expand/collapse menu.

Word of the Day

Subscriber Help

Expand/collapse menu.

More Word Games

Daily Crosswords

Expand/collapse menu.

Open Dictionary

Alphabetical Browse

Browse Categories

Submit an Entry

Expand/collapse menu.

Spelling Bee Hive

Hive Headquarters

Spelling Champion

Spelling Reform

Expand/collapse menu.

Word for the Wise

Today's Broadcast

Expand/collapse menu.

Books and CD-Roms

Online Services

Palm and Pocket PC

Expand/collapse menu.

Looking Up a Word

Citing the Dictionary

Audio Pronunciations

Word Games Help

Expand/collapse menu.

Merriam-Webster FAQ

Advertising Info

Copyright Notice

Hooked Media

Also Visit:
Unabridged
Visual

ESL:
Learner's
for Kids:
Word Central

Browse the Dictionary:: A; B; C; D; E; F; G; H; I; J; K; L; M; N; O; P; Q; R; S; T; U; V; W; X; Y; Z; #

keystone

One entry found.

Entry Word: keystone

Function: noun

Meaning: an immaterial thing upon which something else rests <complete honesty is the keystone of our friendship> — see base 1

Learn more about "keystone"

Learn more about "keystone" and related topics at Britannica.com