67 tardus, tard-a, tardumlate

tūtus, tūt-a, tūtumsafe

“Some US-A-UM adjectives end with er in the masculine nominative singular instead of us. These nominative forms are like the noun puer, which also has er instead of us in the nominative singular. The other forms are all regular; remember that the stem is the Feminine form minus –a. This is the reason why I teach you to make the stem from the feminine form, not the masculine one; it’s for cases like this, where the masculine has er.”

miser, miser-a, miserummiserable