Wordorigins.org

This is a slang phrase with many variants. The verb is usually either hawk or hock and the subject varies between loogie, louie, and lunger. It means to cough up phlegm and dates to the 1970s.

Hawk is an old verb meaning to clear the throat or cough up phlegm. It dates to the late 16th century and is probably echoic in origin. From Richard Mulcaster’s 1581 Positions:

For hauking vp of blood.