Diction, or word choice, is important to poetry and also to the most widespread example of poetry, the lyrics of songs.
“A primary distinction between the practical use of language and the literary use is that in literature, especially in poetry, a fuller use is made of individual words. To understand this, we need to examine the composition of a word.
The average word has three component parts: sound, denotation, and connotation. It begins as a combination of tones and noises, uttered by the lips, tongue, and throat, for which the written word is a notation. But it differs from musical tone or a noise in that it has a meaning attached to it. The basic part of this meaning is its denotation or denotations; that is, the dictionary meaning or meanings of the word. Beyond its denotations, a word may also have connotations. The connotations are what it suggests beyond what it expresses: its overtones of meaning. It acquires these connotations from its past history and associations, from the way and the circumstances in which it has been used. The word home, for instance, by denotation means only a place where one lives, but by connotation it suggests security, love, comfort, and family. The words childlike and childish both mean “characteristic of a child,” but childlike suggests meekness, innocence, and wide-eyed wonder, while childish suggests pettiness, willfulness, and temper tantrums. If we list the names of different coins―nickel, peso, lira, shilling, sen, doubloon―the word doubloon, to four out of five readers, immediately will suggest pirates, though a dictionary definition includes nothing about pirates. Pirates are part of its connotation.
Connotation is very important in poetry, for it is one of the means by which the poet can concentrate or enrich meaning―say more in fewer words.”