-ate1

1.
a suffix occurring in loanwords from Latin, its English distribution paralleling that of Latin. The form originated as a suffix added to a- stem verbs to form adjectives (separate). The resulting form could also be used independently as a noun (advocate) and came to be used as a stem on which a verb could be formed (separate; advocate; agitate). In English the use as a verbal suffix has been extended to stems of non-Latin origin: calibrate; acierate .
Origin
< Latin -ātus (masculine), -āta (feminine), -ātum (neuter), equivalent to -ā- thematic vowel + -tus, -ta, -tum past participle suffix

-ate2

1.
a specialization of -ate1 , used to indicate a salt of an acid ending in -ic , added to a form of the stem of the element or group: nitrate; sulfate .
Compare -ite1 .
Origin
probably originally in Neo-Latin phrases, as plumbum acetātum salt produced by the action of acetic acid on lead

-ate3

1.
a suffix occurring originally in nouns borrowed from Latin, and in English coinages from Latin bases, that denote offices or functions (consulate; triumvirate; pontificate), as well as institutions or collective bodies (electorate; senate); sometimes extended to denote a person who exercises such a function (magistrate; potentate), an associated place (consulate), or a period of office or rule (protectorate). Joined to stems of any origin, ate3, signifies the office, term of office, or territory of a ruler or official (caliphate; khanate; shogunate).
Origin
< Latin -ātus (genitive -ātūs), generalized from v. derivatives, as augurātus office of an augur (augurā(re) to foretell by augury + -tus suffix of v. action), construed as derivative of augur augur
British Dictionary definitions for -ate

-ate1

suffix
1.
(forming adjectives) possessing; having the appearance or characteristics of: fortunate, palmate, Latinate
2.
(forming nouns) a chemical compound, esp a salt or ester of an acid: carbonate, stearate
3.
(forming nouns) the product of a process: condensate
4.
forming verbs from nouns and adjectives: hyphenate, rusticate
Word Origin
from Latin -ātus, past participial ending of verbs ending in -āre

-ate2

suffix
1.
denoting office, rank, or a group having a certain function: episcopate, electorate
Word Origin
from Latin -ātus, suffix (fourth declension) of collective nouns
Word Origin and History for -ate

word-forming element used in forming nouns from Latin words ending in -atus, -atum (e.g. estate, primate, senate). Those that came to English via Old and Middle French often arrived with -at, but an -e was added after c.1400 to indicate the long vowel.

The suffix also can mark adjectives, formed from Latin past participals in -atus, -ata (e.g. desolate, moderate, separate), again, they often were adopted in Middle English as -at, with an -e appended after c.1400.

verbal suffix for Latin verbs in -are, identical with -ate (1). Old English commonly made verbs from adjectives by adding a verbal ending to the word (e.g. gnornian "be sad, mourn," gnorn "sad, depressed"), but as the inflections wore off English words in late Old and early Middle English, there came to be no difference between the adjective and the verb in dry, empty, warm, etc. Thus accustomed to the identity of adjectival and verbal forms of a word, the English, when they began to expand their Latin-based vocabulary after c.1500, simply made verbs from Latin past-participial adjectives without changing their form (e.g. aggravate, substantiate) and it became the custom that Latin verbs were anglicized from their past participle stems.

in chemistry, word-forming element used to form the names of salts from acids in -ic; from Latin -atus, -atum, suffix used in forming adjectives and thence nouns; identical with -ate (1).

The substance formed, for example, by the action of acetic acid (vinegar) on lead was described in the 18th century as plumbum acetatum, i.e. acetated lead. Acetatum was then taken as a noun meaning "the acetated (product)," i.e. acetate. [W.E. Flood, "The Origins of Chemical Names," London, 1963]

-ate in Medicine

-ate suff.

  1. A derivative of a specified chemical compound or element: aluminate.

  2. A salt or ester of a specified acid whose name ends in -ic: acetate.

-ate in Science
-ate  
A suffix used to form the name of a salt or ester of an acid whose name ends in -ic, such as acetate, a salt or ester of acetic acid. Such salts or esters have one oxygen atom more than corresponding salts or esters with names ending in -ite. For example, a sulfate is a salt of sulfuric acid and contains the group SO4, while a sulfite contains SO3. Compare -ite.