mumblyadj.

1847 J. O. Halliwell Dict. Archaic & Provinc. Words II Mumble, to stick together. Suffolk. Sticky soil is said to be mumbly.

1979 Punch 4 July 34/1 Of the meals to be enjoyed in literature or verse, one of my favourites is that of the of the Owl and the Pussycat. ‘They dined on mince and slices of quince.’.. It seems a felicitous combination; tart, crisp quince, soft, mumbly mince.

1849 C. Dickens David Copperfield (1850) viii. 81 When I'm too deaf, and too lame, and too blind, and too mumbly for want of teeth, to be of any use at all, even to be found fault with, then I shall go to my Davy, and ask him to take me in.

1936 Gas Appliance Merchandising May 11/3 A neat appearing salesman and an effective sales talk are often at the mercy of a voice that grates upon the hearer. It may be either too rasping, too high, mumbly, etc.

1980 A. Morice Death in Round ii. 12 I admire his work tremendously, but he has such a mumbly way of talking that I often find myself losing the thread.

2019 New Yorker 16 Dec. 35/2 On the press tour, Jones, their star, was mumbly and glassy-eyed.