The crossword solution for the term SECOND, SO TO SPEAK is ECHO, which is a four-letter word. ECHO is a phenomenon caused by the reflection of sound waves off a surface back to the listener. It is often used in literature and poetry as a metaphor for repetition or reverberation. In this context, the term 'second, so to speak' is referring to the ECHO of a sound, which is heard after the original sound has been made.