Dictionary.com
Thesaurus.com

gnamma hole

American  
[nam-uh hohl] / ˈnæm ə ˌhoʊl /
Also gnamma

noun

Australian.
  1. a hollow in bare rock, narrow at the opening and wider at the bottom, in which water collects.


gnamma hole British  
/ ˈnæmə /

noun

  1. a variant spelling of namma hole

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of gnamma hole

First recorded in 1895–1900; from Nyungar ŋamma, ŋama “a natural well in rock” + hole