ἄκεντρος · akentros — LSJ
stingless, κηφῆνες Pl. R. 552c, 564b; without spur, of a cock, Clyt. 1; without thorns, βάτος Ph. 2.91.
not responding to the spur, of horses, Hippiatr. 105: metaph., of style, pointless, Longin. 21.2.
not occupying a cardinal point, Man. 5.108, Vett.Val. 89.30.