Stretched tightly; strained to stiffness; rigid; not lax; as, a tense fiber.(adjective)
source: webster1913
noun (n)
a grammatical category of verbs used to express distinctions of time(noun.communication)
source: wordnet30
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.(noun)