Just A Mo! is a phrase used to express surprise or disbelief. It is often used in response to something unexpected or outrageous. The crossword solutions for this phrase are SEPT (4 letters) and ONESEC (6 letters). SEPT stands for the Latin phrase 'septem', which means seven, while ONESEC stands for the phrase 'one second', which is used to indicate a brief pause or moment of hesitation. Together, these two words form the phrase 'Just A Mo!', which is used to express surprise or disbelief.