Drop a line and Lay down

Drop a line verb - Communicate (with) in writing.

Lay down and drop a line are semantically related. In some cases you can use "Lay down" instead a verb phrase "Drop a line".

Lay down verb - To put into effect through legislative or authoritative action.

Drop a line and lay down are semantically related. Sometimes you can use "Drop a line" instead a verb "Lay down".