It is quite challenging to find suitable antonyms for the phrase 'leaved open-mouthed.' This phrase describes the state of being completely astonished or amazed, so we need words that convey the opposite meaning. Some antonyms that come to mind include 'unimpressed,' 'bored,' 'disinterested,' 'indifferent,' 'nonplussed,' 'unmoved,' 'unfazed,' and 'unenthused.' These words connote a lack of interest, surprise, or enthusiasm. They indicate a plain or mundane response to a situation or event. However, it is important to note that these words may not be perfect antonyms, as they don't entirely negate the sense of being open-mouthed in the original phrase.