I might offer two possibilities here, both legal terms: from Burton's Legal Thesaurus, 4E. Copyright © 2007 by William C. Burton. Used with permission of The McGraw-Hill Companies, Inc.
SUGGESTIO FALSI. A statement of a falsehood. This amounts to a fraud whenever the party making it was bound to disclose the truth.
SUPPRESSIO VERI. Concealment of truth.
2. In general a suppression of the truth, when a party is bound to disclose it, vitiates a contract. In the contract of insurance a knowledge of the facts is required to enable the underwriter to calculate the chances and form a due estimate of the risk; and, in this contract perhaps more than any other, the parties are required to represent every thing with fairness.
3. Suppressio veri as well as suggestio falsi is a ground to rescind an agreement, or at least not to carry it into execution.