grubble

From grub +‎ -le, frequentative, but compare grabble.

grubble (third-person singular simple present grubbles, present participle grubbling, simple past and past participle grubbled)

1. (obsolete or rare, transitive, intransitive) To feel or grope in the dark.
   • 1704, John Dryden, Poetical Miscellanies, volume 5, London, translation of Amores by Ovid, page 28:

     When all depart, when Complements are loud, / Be sure to mix among the thickest Crowd: / There I will be, and there we cannot miss, / Perhaps to Grubble, or at least to Kiss.

• fumble, grabble; see also Thesaurus:feel around

“grubble”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.