formerly -at, forming participial adjectives from L. pa. pples. in -ātus, -āta, -ātum, being only a special instance of the adoption of L. pa. pples. by dropping the inflexional endings, e.g., content-us, convict-us, direct-us, remiss-us, or with phonetic final -e, e.g., complēt-us, finīt-us, revolūt-us, spars-us. The analogy for this was set by the survival of some L. pa. pples. in OF., as confus:—confūsus, content:—contentus, divers:—diversus. This analogy was widely followed in later Fr., in introducing new words from Latin; and both classes of Fr. words, i.e., the popular survivals and the later accessions, being adopted in Eng., provided Eng. in its turn with analogies for adapting similar words directly from L., by dropping the termination. This began about 1400, and as in -ATE1 (with which this suffix is phonetically identical), L. -ātus gave -at, subsequently -ate, e.g., desolātus, desolat, desolate, separātus, separat, separate. Many of these participial adjectives soon gave rise to causative verbs, identical with them in form (see next), to which, for some time, they did duty as pa. pples., as ‘the land was desolat(e by war’; but, at length, regular pa. pples. were formed with the native suffix -ed, upon the general use of which these earlier participial adjs. generally lost their participial force, and either became obs. or remained as simple adjectives, as in ‘the desolate land,’ ‘a compact mass.’ (But cf. situate = situated.) So aspirate, moderate, prostrate, separate; and (where a vb. has not been formed), innate, oblate, ornate, sedate, temperate, etc. As the Fr. repr. of L. -atus is -é, English words in -ate have also been formed directly after Fr. words in -é, e.g., affectionné, affectionate.
2. As with Eng. -ed, L. ppl. adjs. in -ātus were also formed on nouns, etc., when no other part of the vb. was required, as cauda tail, caudātus tailed, and often with negatives, as sensus sense, insensātus unprovided with sense. In modern times these have been liberally adopted in Eng., and on their analogy, or that of corresponding Fr. words in -é, new words are constantly formed where L. actually had not the formation, as apiculate, f. apiculus a little point; lunulate, f. lunula little moon; roseate, f. roseus rosy; angustifoliate, f. angustum narrow + folium leaf.
3. Many words, originally adj., are also used substantively, e.g., delegate, reprobate, precipitate, carbonate, alcoholate, and have gone to reinforce the number of the earlier sbs. in -ATE1, q.v.
