LINE CHARGE, a prolonged spell of uncontrolled laughter or crying which may be continued for several hours. Once started a Line charge can usually be reinforced by the occasional interjection of almost any word or phrase by the auditor. The Line charge usually signals the sudden release of a large amount of charge and brings about a marked change in the case. (COHA, p. 281)
Hubbard, L. R., (1975) Dianetics and Scientology Technical Dictionary. Los Angeles: Church of Scientology of California Publications Organization.