A lawsuit filed by the debtor or other estate representative seeking to “avoid” (nullify) certain transfers made by the debtor. Fraudulent transfer actions and preference actions are forms of avoidance actions as are certain exercises of the strong arm powers under Section 544 and actions to avoid certain postpetition transfers under Section 549.
Bankruptcy Code §§ 544-550. See also Fraudulent Transfer, Preference, Strong Arm Powers.