Abstract: A washing machine appliance and a fluid additive dispenser therefor. The washing machine appliance includes a wash tub and a wash basket rotatably mounted within the wash tub, a gap is defined between the wash tub and the wash basket. The fluid additive dispenser includes a reservoir with a siphon tube and a siphon cap. The siphon cap includes an overflow inlet. The fluid additive dispenser is in fluid communication with the wash tub and the wash basket only via an outlet of the siphon tube. The siphon tube outlet is positioned for directing fluid into the gap between the wash tub and the wash basket.