elight_. moenia, _city walls_.
divitiae, _riches_. minae, _threats_.
Idus, _Ides_. nuptiae, _marriage_.
indutiae, _truce_. posteri, _descendants_.
insidiae, _ambush_. reliquiae, _remainder_.
majores, _ancestors_. tenebrae, _darkness_.
verbera, _blows_.

Also in classical prose regularly--

cervices, _neck_. nares, _nose_.
fides, _lyre_. viscera, _viscera_.

Nouns used only in Certain Cases.

57. 1. Used in only One Case. Many nouns of the Fourth Declension are found
only in the Ablative Singular as, jussu, _by the order_; injussu, _without
the order_; natu, _by birth_.

2. Used in Two Cases.

a. Fors (_chance_), Nom. Sing.; forte, Abl. Sing.

b. Spontis (_free-will_), Gen. Sing.; sponte, Abl. Sing.

3. Used in Three Cases. Nemo, _no one_ (Nom.), has also the Dat. nemini and
the Acc. neminem. The Gen. and Abl. are supplied by the corresponding cases
of nullus; viz. nullius and nullo.

4. Impetus has the Nom., Acc., and Abl. Sing., and the Nom. and Acc. Plu.;
viz. impetus, impetum, impetu, impetus.

5. a. Preci, precem, prece, lacks the Nom. and Gen. Sing.

b. Vicis, vicem, vice, lacks the Nom. and Dat. Sing.

6. Opis, dapis, and frugis,--all lack the Nom. Sing.

7. Many monosyllables of the Third Declension lack the Gen. Plu.: as, cor,
lux, sol, aes, os (oris), rus, sal, tus.

Indeclinable Nouns.

58. Here belong--

fas, n., _right_. nefas, n., _impiety_.
instar, n., _likeness_. nihil, n., _nothing_.
mane, n., _morning_. secus, n., _sex_.

1. With the exception of mane (which may serve also as Ablative, _in the
morning_), the nouns in this list are simply Neuters confined in use to the
Nominative and Accusative Singular.

Heteroclites.

59. These are nouns whose forms are partly of one declension, and partly of
another. Thus:--

1. Several nouns have the entire Singular of one declension, while the
Plural is of another; as,--

vas, vasis (_vessel_); Plu., vasa, vasoroum, vasis, etc.
jugerum, jugeri (_acre_); Plu., jugera, jugerum, jugeribus, etc.

2. Several nouns, while belonging in the main to one declension, have
certain special forms belonging to another. Thus:--

a) Many nouns of the First Declension ending in -ia take also a Nom. and
Acc. of the Fifth; as, materies, materie