unprovoked

adj.

（尤指暴力言行）未受招惹而自发的，无缘无故的；

1. This malicious and unprovoked attack astounded him.
   这个恶意的无端攻击使他吃惊。
2. The boys' attack on the old woman was quite unprovoked.
   那帮男孩对老妇人的袭击完全是无来由的。

Factors prognostic of unprovoked seizures after febrile convulsions.
Risk of recurrent seizures after two unprovoked seizures
ADHD as a risk factor for incident unprovoked seizures and epilepsy in children.
Depression and suicide attempt as risk factors for incident unprovoked seizures.
The risk of seizure recurrence after a first unprovoked afebrile seizure in childhood: an extended follow-up.
Incidence and Clinical Characterization of Unprovoked Seizures in Adults: A Prospective Population‐Based Study
Systematic review and meta-analysis of incidence studies of epilepsy and unprovoked seizures.
Newly diagnosed unprovoked epileptic seizures: presentation at diagnosis in CAROLE study. Coordination Active du Reseau Observatoire...
Risk assessment of recurrence in patients with unprovoked deep vein thrombosis or pulmonary embolism: the Vienna prediction model.
Randomized clinical trial on the efficacy of antiepileptic drugs in reducing the risk of relapse after a first unprovoked tonic‐clo...