The word "半胱氨酸" is formed by combining the character "半" (half) with "胱氨酸" (cystine), where "半" indicates cysteine is structurally derived from cystine as its reduced form, "胱" approximates the sound "cys" from the English name, and "氨酸" specifies it as an amino acid, resulting in a term that blends phonetic and semantic translation for the biochemical compound.