grot UK /ɡɹɒt/US /ɡɹɑt/ noun3 •(UK, slang) Any unpleasant substance or material. •(UK, slang) A miserable person. •(literary) A grotto.She took me to her elfin grot, / And there she wept, and sigh'd full sore, / And there I shut her wild wild eyes / With kisses four. — 1819 formsgrots