girthEnglishOxford English Thesaurusgirth noun 1 a tree that was 150 feet in height and 10 feet in girth: circumference, width, perimeter; size, bulk, measure. 2 he tied the towel around his girth: stomach, midriff, middle, abdomen, belly, gut; informal tummy, tum. 3 a horse's girth: North American cinch.girth Oxford Dictionary of English