The word 沙发 (shāfā) is a direct phonetic borrowing from the English word "sofa". It is formed by selecting two existing Chinese characters whose pronunciations, when combined, closely approximate the sound of the foreign word: 沙 (shā) for "so" and 发 (fā) for "fa". This method of creating new words is called transliteration. While primarily sound-based, the character 发 can subtly imply a sense of "issuing" or "spreading out", which loosely corresponds to the function of the furniture, though this semantic connection is secondary to the primary phonetic purpose.