[I. COMPOSITION OF NOUNS.]
FORM OF COMPOUNDS.
[379]. If the first part is a noun, its stem is taken: as, Ahēno-barbus, Redbeard, Barbarossa; usually with weakening of a stem vowel ([103-105]): as, aurifex, jeweller (auro-). On other changes of the final vowel in the first member of compounds, see [174]. Sometimes with disappearance of a syllable ([179]); as, *venēni-ficus, venē-ficus, poisoner (venēno-); or of a vowel ([111]): as, man-ceps, contractor (manu-); particularly before a vowel ([119]): as, magn-animus, great-souled (magno-). Consonant stems are often extended by i before a consonant: as, mōri-gerus, complaisant (mōr-).
[380]. Stems in -s-, including those in -er-, -or- and -ōr- ([236]), are sometimes compounded as above ([379]): as, nemori-vagus, woodranger; honōri-ficus, complimentary; but usually they drop the suffix and take i: as, opi-fex, work-man (oper-); foedi-fragus, truce-breaker (foeder-); volni-ficus, wounding (volner-); mūni-ficus, generous (mūner-); terri-ficus, awe-inspiring (terrōr-); horri-fer, dreadful, horri-sonus, awful-sounding (horrōr-).
[381]. The second part, which often has weakening of the vowel ([102]), is sometimes a bare root used as a stem ([199]), oftener a root with a formative suffix; or a noun stem, sometimes with its stem ending modified: as, iū-dic-, N. iūdex, juror (√dic-, declare); causi-dic-o-, N. causidicus, pleader ([209]); in-gen-io-, N. ingenium, disposition (√gen-, beget, [219]); con-tāg-iōn-, N. contāgiō, touching together (√tag-, touch, [227]); im-berb-i-, N. imberbis, beardless (barbā-).
MEANING OF COMPOUNDS.
[382]. Determinatives are compounds in which the second part keeps its original meaning, though determined or modified by the first part. The meaning of a determinative may often be best expressed by two words.
[383]. (1.) The first part of a determinative may be an adjective, an adverb, a preposition, or an inseparable prefix; the second part is a noun: as,
lāti-fundium, i.e. lātī fundī, broad acres; prīvi-lēgium, i.e. prīva lēx, special act; alti-sonāns, i.e. altē sonāns, high-sounding; con-discipulus, i.e. cum alterō discipulus, fellow-pupil; per-magnus, i.e. valdē magnus, very great; in-dignus, i.e. nōn dignus, unworthy.