noun
A person who agrees with or supports a particular group, idea, or movement, often without being an active member. Used in political, social, or ideological contexts.
彼はその政党のシンパサイザーだが、党員ではない。
He is a sympathizer of that political party, but not a member.
過激派のシンパサイザーが集
Sympathizers of the radical group held a rally.