A word, statement, or situation with two or more possible meanings is said to be ambiguous. As poet and critic William Empson wrote in his influential book Seven Types of Ambiguity
(1930), “The machinations of ambiguity are among the very roots of poetry.” A poet may consciously join together incompatible words to disrupt the reader’s expectation of meaning, as e.e. cummings does in [anyone lived in a pretty how town]
. The ambiguity may be less deliberate, steered more by the poet’s attempts to express something ineffable, as in Gerard Manley Hopkins’s “The Windhover.”
At the sight of a bird diving through the air, the speaker marvels, “Brute beauty and valor and act, oh, air, pride, plume here / Buckle!” The ambiguity of this phrase lies in the exclamation of “buckle”: The verb could be descriptive of the action, or it could be the speaker’s imperative. In both cases, the meaning of the word is not obvious from its context. “Buckle” could mean “fall” or “crumple,” or it could describe the act of clasping armor and bracing for battle.