Another word for ‘idiot’ and related terms. It feels dated, though it has a nice ring to it; ‘chump’ is another one – my grandfather used it on us. The dictionary says ‘galoot’ is informal US and Scottish English, and originally referred to an inexperienced marine. ‘Captain Flint, you chump-headed galoot,’ said Captain Nancy.
Source: Arthur Ransome, Swallows and Amazons (London: Vintage, 2015 (1930)), p. 156