The term "galoot" is a slang expression that has been used in American English since at least the early 20th century. It can be used as both a noun and an adjective, but its primary meaning refers to someone who is foolish or stupid - essentially, a clumsy or awkward person.
As a noun, "galoot" can refer to a specific individual who fits this description, while as an adjective it can be used to describe something that is clumsy, uncoordinated, or just generally lacking in grace or skill - for example, someone might say "that galoot couldn't even walk without tripping over his own feet!"
The origins of the word are unclear, but it has been suggested that it may have originated from a similar-sounding Spanish term meaning "stupid" or "foolish." Regardless of its etymology, today "galoot" is primarily used in informal speech and writing, and should be avoided in more formal contexts.