soursop \ˈ ̷ ̷ˌ ̷ ̷\noun Etymology:sour (I) + sop (food) 1.: a small tropical American tree (Annona muricata) 2.: the large succulent irregularly ovoid fruit of the soursop tree having short fleshy spines and a slightly acid fibrous pulp — called also guanabana; compare sweetsop