run aground /ˌrʌn əˈɡraʊnd/ verb2 •To be immobilized by water too shallow to allow it to float.The ship ran aground and had to be towed back out to sea. •To cause (a vessel) to be immobilized by water too shallow to allow it to float.The drunken helmsman ran the ship aground. formsran aground · running aground · runs aground