Noun
A lacunar stroke or infarct.
2018, The New England Journal of Medicine, →DOI:We compared the efficacy and safety of rivaroxaban […] with aspirin […] for the prevention of recurrent stroke in patients with recent ischemic stroke that was presumed to be from cerebral embolism but without arterial stenosis, lacune, or an identified cardioembolic source.
A lacuna.
Source: en.wiktionary.org