<p><strong>Verb (used with object):</strong></p><ul><li>to make or cause to seem smaller, less, less important, etc.; lessen; reduce.</li><li>to withhold or deny consent to do, enter into or upon, etc.; refuse: He declined to say more about it.</li><li>to express inability or reluctance to accept; refuse with courtesy: to decline an invitation; to decline an offer.</li><li>to cause to slope or incline downward.</li><li>to inflect (a noun, pronoun, or adjective), as Latin puella, declined puella, puellae, puellae, puellam, puella in the five cases of the singular.</li><li>to recite or display all or some subset of the inflected forms of a noun, pronoun, or adjective in a fixed order.</li></ul><p><strong>Verb (used without object):</strong></p><ul><li>to express courteous refusal; refuse: We sent him an invitation but he declined.</li><li>to bend or slant down; slope downward; descend: The hill declines to the lake.</li><li>to follow a downward course or path: The sun declined in the skies.</li><li>to draw toward the close, as the day.</li><li>to fail in strength, vigor, character, value, etc.; deteriorate.</li><li>to fail or dwindle; sink or fade away: to decline in popularity.</li><li>to descend, as to an unworthy level; stoop.</li><li>to be characterized by declension.</li></ul><p><strong>Noun:</strong></p><ul><li>a downward slope; declivity.</li><li>a downward movement, as of prices or population; diminution: a decline in the stock market.</li><li>a failing or gradual loss, as in strength, character, power, or value; deterioration: the decline of the Roman Empire.</li><li>a gradual deterioration of the physical powers, as in later life or in disease: After his seventieth birthday he went into a decline.</li><li>progress downward or toward the close, as of the sun or the day.</li><li>the later years or last part: He became an editor in the decline of his life.</li></ul>