thumbful--prophetes.ai

thumbful
  (ˈθʌmfʊl)
  [f. thumb n. + -ful.]
  As much as a thumb can hold.

1930 E. Pound XXX Cantos xxii. 109 He..pulled out his snuff-box, And sniffed up a thumb-full. 1957 [see riffle v. 3 b].

Oxford English Dictionary