Appendix:Latin fifth declension
Latin nouns of the fifth declension end in -ēs in the nominative singular, with a genitive in -ēī (after -i-) or in -ĕī (after consonant), and have an invariable stem. Aside from rēs, spēs, and fidēs, fifth-declension nouns generally end more specifically in -iēs. Some nouns show variation between fifth-declension forms in -iēs and first-declension forms in -ia.
The plural forms of most fifth declension nouns are uncommon.