What is the meaning of -at?

used to form toponyms. -ian

forms the masculine singular past participle of verbs whose infinitives end in -ar

forms adjectives, from nouns, meaning “which contains the suffixed noun”

forms nouns, from the names of types of professionals, meaning the position of being that type of professional; -dom

a common ending for many infinitive verbs

forms imperfective verbs

forms iterative verbs

used to form nouns

-ate (abstract noun), -ship, -hood, -age, -cy

2. forms nouns denoting a rank or office

   forms nouns denoting a rank or office

   forms nouns denoting the territory or the social or political system ruled by a person or people of a certain rank or office

   forms nouns denoting the concrete charge, context of a rank or office

   forms nouns denoting a group of officials associated with a rank or office

   forms nouns denoting a state associated with one's social situation

   forms nouns denoting a place where people in a certain state are found

   found in borrowed Latin past participles (sometimes nominalized)

   forms the noun denoting the result, product, object, or effect of the action expressed by a verb

   -ate (abstract noun)

   found in borrowed Latin past participles

   found in borrowed masculine nominalized Latin past participles

   found in borrowed Latin nouns denoting the result, product, object, or effect of the action expressed by a Latin verb; often corresponding to a German verb in -ieren

   -ate

   third-person singular present active indicative of -ō

   third-person singular perfect active indicative of -ō

   Suffix used to derive the plural and feminine form of certain nouns derived from Arabic.

   alternative form of -iet (noun plural suffix)

   Forms adjectives indicating something that is possessed as a characteristic.

   Forms adjectives from stems, without any particular meaning. Often, the more basic stem is an adverb, the adjective's own attributive form, or has fallen out of use altogether.

   Form of the suffix -a used with odd-syllable stems.

   used to form nouns

   used to form nouns

   negative verbal suffix; does not

   Second person plural suffix

   forms masculine nouns; -ate, -age

   Used with a stem to form the masculine singular past participle of regular -a (first conjugation) verbs.

   Used on nominal and verbal stems of loanwords, rarely of native words, to build nouns of various meanings.

   1. Denoting a person.

      Denoting a person.

      Denoting a room, building or field.

      Denoting an honor or service.

      Denoting collectivity.

      Denoting things.

      Denoting abstract notions.

      Forms plurals from words of Arabic origin.

      Forms collective nouns.

      Forms nouns referring to fields of knowledge or practice.

      Used to indicate an amount

      Source: wiktionary.org