The Collaborative International Dictionary of English v.0.48:
Stumble \Stum"ble\, v. i. [imp. & p. p. Stumbled; p. pr. & vb.
n. Stumbling.] [OE. stumblen, stomblen; freq. of a word
akin to E. stammer. See Stammer.]
1. To trip in walking or in moving in any way with the legs;
to strike the foot so as to fall, or to endanger a fall;
to stagger because of a false step.
There stumble steeds strong and down go all.
The way of the wicked is as darkness: they know at
what they stumble. --Prov. iv.
2. To walk in an unsteady or clumsy manner.
He stumbled up the dark avenue. --Sir W.
3. To fall into a crime or an error; to err.
He that loveth his brother abideth in the light, and
there is none occasion og stumbling in him. --1 John
4. To strike or happen (upon a person or thing) without
design; to fall or light by chance; -- with on, upon, or
Ovid stumbled, by some inadvertency, upon Livia in a
Forth as she waddled in the brake,
A gray goose stumbled on a snake. --C. Smart.