Overview
Third-declension consonant stems include many Latin nouns and Greek loanwords, and the comparative adjectives ending in -ior/-ius are used to show position. This topic covers Greek third-declension terms, the -ior/-ius adjectives, third-declension adjectives and the combining term-elements of consonant-stem nouns.
Greek terms of the third declension
Many clinical terms of Greek origin are declined as third-declension consonant stems. The commonest types are neuter nouns in -ma, -matis and nouns with the genitive in -ngis, -acis or -idis.
Locative adjectives in -ior/-ius
Adjectives that show the position of a structure are comparatives. They end in -ior in the masculine and feminine and in -ius in the neuter; the genitive singular is -oris, the ablative singular -e, the nominative plural -ores (neuter -ora) and the genitive plural -orum.
Examples: musculus rectus superior, facies anterior, margo posterior, extremitas inferior.
Third declension adjectives
Third Declension Adjectives
Third declension adjectives are usually declined like third declension pure i-stem nouns, but the masculine and feminine adjectives have Acc. Sg. -em.
These adjectives have a common form for masculine and feminine in Nom. Sg. and a separate form for neuter.
The masculine and feminine ending is -is.
The neuter ending is -e.
omnis, e - all, each, everyone
brevis, e - short
juvenilis, e - juvenile
levis, e - light
mollis, e - mild, soft
senilis, e - senile
sterilis, e - sterile
tenuis, e - tender, slim
Many adjectives ending in suffixes common in medicine belong to this group, especially in anatomy.
These suffixes often show relation to a body part and replace the Gen. Sg. ending of nouns.
For example: pulmo, pulmon-is becomes pulmon-alis, e and maxilla, maxilla-ae becomes maxill-aris, e.
These adjectives often retain their Latin form in English, but lose the -is, -e ending.
-alis, ale and -aris, are: Indicate relation to or connection with an organ or body part.
-bilis, bile: Suggests ability or possibility (e.g., inoperabilis, e meaning "(in)operable").
-formis, forme: Shows similarity and corresponds to the Greek second declension adjectives ending in -oideus, a, um.
Most were created and introduced to medical terminology in the 17th century.
cruciformis, e - cruciform
formis, e - form
fungiformis, e - fungiform
piriformis, e - piriform
pisiformis, e - pisiform
sacciformis, e - sacciform
stabilis, e: means "(un)stable".
These have a single nominative singular form for all genders.
A genitive singular ending is used as an inflection.
Nom. Sg. -ex, Gen. Sg. -icis
simplex, icis - simple
multiplex, icis - multiple
duplex, icis - double