We can swiftly review a number of adjective-forming suffixes that were regularly added to the LATIN PRESENT INFINITIVE BASE.
1. -AX. This suffix could be combined with a present verb base (e.g., ten-ere, “hold”) to form a 3rd declension adjective of the type tenax, tenac-is, “inclined to hold,” with English derivatives like tenacious and tenacity (L ten-ac-itas). Here is a sample:
|LATIN INFINITIVE||LATIN MEANING||LATIN ADJECTIVE||ENGLISH DERIVATIVES|
2. -UUS. We met several of these adjectives in Chapter 4 (§26), though you weren’t told at the time that they derived from verbs. If nocēre is “to harm,” then nocuus (E nocuous) is “inclined to harm,” “harmful,” and innocuus (E innocuous) is its opposite. The root of tangere appears as tig- in contiguus; so English contiguous means “touching together.” From con-tinere (“hold together”) came continuus, whence continuous and continuity. Deciduus is derived from de-cidere, a compound of cadere; therefore deciduous leaves are “inclined to fall down.” What is the etymology of conspicuous?
3. -ULUS. Very similar in meaning, this suffix had limited use in Latin. Bibulus (< bibere) is the etymon of English bibulous (“tending to drink”), and tremulus (< tremere), of tremulous (“inclined to tremble”). Other English examples are pendulous (pendere, “hang”), querulous (queri, “complain”), and garrulous (garrire, “chatter”).
4. -IDUS. These adjectives often correspond with deverbative nouns in -or, of the type introduced in §74. Thus timēre (“to fear”) gave rise to the noun timor (reflected in E timorous) and the adjective timidus (“inclined to fear”) > English timid. Similarly,
|pallēre (“to be pale”)||> pallor (noun)||pallidus (adj.), E pallid|
|rigēre (“to be stiff”)||> rigor||rigidus, E rigid|
|tumēre (“to swell”)||> tumor||tumidus, E tumid [cf. tumescent, -ence]|
Other English adjectives of this type include: fervid, liquid, livid, stupid, squalid, valid, vapid, lucid, rapid, and vivid.
- The -acious ending on tenacious is derived from French tenacieux, which was influenced by the Latin -osus type of adjective. There was never a Latin form “tenaciosus.” ↵
- All but the last three have corresponding -or nouns, both in Latin and in English. Except for rapid (rapere) and vivid (vivere) all these adjectives are derived from 2nd conjugation verbs. ↵