drop a line
Correspond, write a short letter or note. For example, I hope you'll drop me a line soon. This idiom uses line in the sense of “a few words in writing,” a usage first recorded in 1647.
Words nearby drop a line
droopy,
drop,
drop a bombshell,
drop a brick,
drop a dime,
drop a line,
drop arch,
drop away,
drop back,
drop bear,
drop behind