Just as Tolkien experimented with various words for “debt, trespass” (e.g. luhta or rohta), he also experimented with various words for “debtor, trespasser” in drafts of the Átaremma prayer from the 1950s. In the earliest drafts Tolkien had lucando or lucindo (VT43/8-10), but in the third version he had (plural) rocindi (VT43/11), which in the fourth version was revised to (plural) rucindi >> ruhtalie >> rohtalië (VT43/11-12). In the final two versions Tolkien reformulated the phrase, saying “those who trespass against us” rather than “trespassers” (VT43/12).

The forms rocindi/rucindi appear only in the plural, but their singular is probably rocinde/rucinde. The form rohtalie is clearly rohta “*debt, trespass” + lië “people”.

Neo-Quenya: Since I retain rohta “*debt” for purposes of Neo-Quenya, I would retain rocinde “*debtor” as well. However, Helge Fauskanger mostly used *rohtando for “debtor” in his Neo-Quenya New Testament (NQNT). In some places Fauskanger used rohtalie as an alternate plural formation for “debtors”, and I would as well.