The term 'Brief Flash' can be broken down into four crossword solutions: GLEAM (5 letters), SPASM (5 letters), GLINT (5 letters), and SEC (3 letters). GLEAM is a verb meaning to shine brightly or to emit a soft, steady light. SPASM is a noun meaning a sudden, involuntary contraction of a muscle. GLINT is a verb meaning to shine with a bright, brief flash of light. Finally, SEC is an abbreviation for the word second, which is a unit of time equal to one sixtieth of a minute. Together, these words describe a brief flash of light that lasts only a second.