Word choice is also known as diction in poetry. In this poem, Hughes' diction is both simple and poetic. It is simple because he uses mostly everyday words that ordinary people would know, such as "dry," "raisin," "sun," and "meat." It is written in poetic diction, however, it uses figurative language. Figurative language goes beyond the literal to enhance the meaning or the feeling of the words chosen.
For example, Hughes uses a series of similes—comparisons using the words like or as—to compare a dream deferred (put off) to a raisin drying up in the sun, to a festering (pus-filled, infected) sore, to rotten meat, to a crusted sweet, and to a load that sags. The similes are all images: descriptions that use the fives senses of sight, sound, taste, smell, or touch. We can visualize a drying raisin or an infected sore, feel the weight of a sagging load, and smell the stink of rotting meat. These are all unpleasant images that build up in our mind the sourness and pain of not being able to fulfill one's dreams.
The poem also uses poetic diction in its rhyme scheme: "sun" and "run," and "meat" and "sweet" rhyme, asking a series of questions that provoke a reader to think. Although the words are simple, they leave a strong impression.