Quasi-complete disjunction occurs when the second clause is semantically related to the first, yet joining them with wāw would tempt the listener toward an unintended coordination and hence a misleading interpretation. Faṣl protects the intended meaning.
This is not complete disjunction, because a genuine thematic connection can exist. The term “quasi” reflects that the omission of wāw is not due to total unrelatedness, but to the risk of a false syntactic or semantic attachment.