nextcloud/settings/l10n/cy_GB.php

<?php $TRANSLATIONS = array(
"Invalid request" => "Cais annilys",
"Error" => "Gwall",
"Delete" => "Dileu",
"Security Warning" => "Rhybudd Diogelwch",
"Password" => "Cyfrinair",
"New password" => "Cyfrinair newydd",
"Other" => "Arall"
);