The word 'sympathizer' is built upon the Greek-derived concept of shared feeling. The prefix sym- (a variant of syn-, meaning "together") combines with the root -path- (from pathos, meaning "feeling" or "suffering") to form the core idea of "feeling with" another. This concept entered English via Latin and French, first as the noun 'sympathy'. The verb 'sympathize' was later formed by adding the Greek-derived verbal suffix -ize. Finally, the agent noun suffix -er (from Old English and Germanic, often via Latin -ator) was appended to create 'sympathizer', literally "one who feels with," designating a person who shares the feelings or supports the cause of another.

Structure: sym (together) + path (feeling) + izer (agent noun suffix) - sym: A prefix of Greek origin (from syn-), meaning "together, with". Its role is to indicate association or union. - path: A root of Greek origin (from pathos), meaning "feeling, suffering, experience". It forms the core semantic base of the word. - izer: A suffix of Latin/Greek origin via French and English, forming agent nouns meaning "a person who does or is concerned with (something)". Its role is to convert the verb 'sympathize' into a noun denoting a person.