tense

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Tightly stretched; taut. See Synonyms at stiff, tight.
2. adj. In a state of mental or nervous tension.
3. adj. Characterized by nervous tension or suspense.
4. adj. Linguistics Enunciated with taut muscles, as the sound (ē) in keen.
5. v. To make or become tense.
6. n. Any one of the inflected forms in the conjugation of a verb that indicates the time, such as past, present, or future, as well as the continuance or completion of the action or state.
7. n. A set of tense forms indicating a particular time: the future tense.

Century Dictionary and Cyclopedia

1. n. Time. See temps.
2. n. In grammar: Time.
3. n. One of the forms, or sets of forms, which a verb takes in order to indicate the time of action or of that which is affirmed: extended also to forms indicating the nature of the action as continued, completed, and the like. In English this is effected either by internal vowel change, as in sing, sang, lead, led; by terminational inflection, as in love, loved; or, in verb-phrases, by means of auxiliary words, as in did love, have loved, will love.
4. Being in a state of tension; stretched until tight; strained to stiffness; rigid; not lax: often used figuratively.
5. To make tense or taut.

Wiktionary

1. n. Any of the forms of a verb which distinguish when an action or state of being occurs or exists.
2. adj. Showing signs of stress or strain; not relaxed.
3. adj. Pulled taut, without any slack.
4. v. To make or become tense.

GNU Webster's 1913

1. n. One of the forms which a verb takes by inflection or by adding auxiliary words, so as to indicate the time of the action or event signified; the modification which verbs undergo for the indication of time.
2. adj. Stretched tightly; strained to stiffness; rigid; not lax.

WordNet 3.0

1. v. become tense, nervous, or uneasy
2. n. a grammatical category of verbs used to express distinctions of time
3. adj. in or of a state of physical or nervous tension
4. adj. pronounced with relatively tense tongue muscles (e.g., the vowel sound in `beat')
5. v. become stretched or tense or taut
6. v. cause to be tense and uneasy or nervous or anxious
7. v. increase the tension on
8. adj. taut or rigid; stretched tight