The crossword solutions for the term 'Brief Moment, Briefly' are MSEC (4 letters) and SEC (3 letters). MSEC stands for Millisecond and SEC stands for Second. A millisecond is one thousandth of a second, and a second is a unit of time equal to the duration of 9, 192, 631, 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. Therefore, a brief moment, briefly, can be described as a millisecond or a second.