Drop a line and Drop line

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

Drop line and drop a line are semantically related In some cases you can replace phrase "Drop line" with "Drop a line", this phrases are similar.

Drop line noun - A headline with the top line flush left and succeeding lines indented to the right.

Drop a line and drop line are semantically related in communicate topic. Sometimes you can use "Drop a line" instead a verb phrase "Drop line", if it concerns topics such as fish, put language down on paper, mutually exchange information, communicate in writing.