A more thorough explanation:

Definition: Ne unques accouple (nee-skwēz-kwəp-əl), n. [Law French “never married”] In a dower action by a widow to recover the estate of her deceased husband, a tenant's plea denying the woman's marriage to the decedent.

Explanation: Ne unques accouple is a legal term that refers to a tenant's plea in a dower action by a widow to recover the estate of her deceased husband. In this plea, the tenant denies the woman's marriage to the decedent. This plea is used to challenge the widow's right to dower, which is a wife's right, upon her husband's death, to a life estate in one-third of the land that he owned in fee.

Example: For example, if a widow files a dower action to recover her deceased husband's estate, the tenant may use the plea of ne unques accouple to deny that the woman was ever married to the decedent. This plea is used to challenge the widow's right to dower and to prevent her from recovering the estate.

Illustration: Let's say John dies, leaving behind a widow named Mary and a tenant named Tom. Mary files a dower action to recover John's estate, but Tom denies that Mary was ever married to John and uses the plea of ne unques accouple to challenge her right to dower. If Tom is successful in his plea, Mary will not be able to recover John's estate.