emphasis

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Special forcefulness of expression that gives importance to something singled out; stress: a lecture on housekeeping with emphasis on neatness; paused for emphasis, then announced the winner's name.
2. n. Special attention or effort directed toward something: a small-town newspaper's emphasis on local affairs.
3. n. Prominence given to a syllable, word, or words, as by raising the voice or printing in italic type.

Century Dictionary and Cyclopedia

1. n. In rhet.: Originally, a figure consisting in a significant, pregnant, or suggestive mode of expression, implying (especially in connection with the context or the circumstances under which an oration is delivered) more than would necessarily or ordinarily be meant by the words used. This figure is of two kinds, according as it suggests either something more than is said, or something purposely not mentioned or professedly not intended. Poets frequently employ it for the former purpose, especially in similes and epithets.
2. n. The mode of delivery appropriate to pregnant or suggestive expression; hence, rhetorical stress; in general, significant stress; special stress or force of voice given to the utterance of a word, succession of words, or part of a word, in order to excite special attention. Emphasis on a syllable differs from syllabic accent by being exceptional in use, and altering the ordinary pronunciation of the word, either by increasing the stress on the syllable regularly accented or by transferring the accent to another syllable: as, a sin may be a sin of o'mis'sion or a sin of com'mission (instead of omis'sion, commis'sion).
3. n. Special and significant vigor or force: as, emphasis of gesticulation; in general, significance; distinctiveness.
4. n. Synonyms Emphasis, Accent, Stress. Emphasis is generally upon a word, but may be upon a combination of words or a single syllable. Accent is upon a syllable: as, the place of the accent in the word “demonstrate” is not fixed. Stress is a synonym for either emphasis or accent. See inflection.

Wiktionary

1. n. Special weight or forcefulness given to something considered important.
2. n. Special attention or prominence given to something.
3. n. Prominence given to a syllable or words, by raising the voice or printing in italic or underlined type.
4. n. typography Related to bold.

GNU Webster's 1913

1. n. (Rhet.) A particular stress of utterance, or force of voice, given in reading and speaking to one or more words whose signification the speaker intends to impress specially upon his audience.
2. n. A peculiar impressiveness of expression or weight of thought; vivid representation, enforcing assent.
3. n. a special attention given to, or extra importance attached to, something.
4. n. something to which great importance is attached.

WordNet 3.0

1. n. special importance or significance
2. n. special and significant stress by means of position or repetition e.g.
3. n. the relative prominence of a syllable or musical note (especially with regard to stress or pitch)
4. n. intensity or forcefulness of expression