I. ˈ ̷ ̷ˌ ̷ ̷ noun
Etymology: thumb (I) + hole
1. : an opening in which to insert the thumb ; specifically : a semicircular cut in the sides or ends of a container to facilitate lifting the cover
2. : a hole in a wind musical instrument opened or closed by the thumb
II. transitive verb
: to provide with a thumbhole