con-

• com-

From Middle English con-, from Latin con-, from cum (“with”).

con-

1. (non-productive) used with certain words to add a notion similar to those conveyed by with, together, or joint

   congenial, congregation, console, consonant, construct, converge, etc.

2. (non-productive) used with certain words to intensify their meaning

   confirm

Con- becomes

col- before l: collaborate;

com- before b, m, and p: combat, commit, compel;

cor- before r: correlation;

It can also appear as co-: coexistence, cosine.

• (together): co-, com-/col-/cor-, syn-/syl-/sym-, inter-

Back-formation from conlang, short for "constructed language".

con-

1. attached to certain words to obtain new, informal, subcultural words in which con- conveys a notion of:
   1. constructed, artificial
   2. hypothetical, fictional
   3. related to conlangs, conworlds, etc.

• CNO, NCO, NOC, OCN, ONC, onc

Ultimately from Latin con-. This etymology is incomplete. You can help Wiktionary by elaborating on the origins of this term.

• IPA^(key): /kɔn/

• Audio

  (file)

con-

1. con- (1)

Inherited from Latin con-, from cum (“with”).

• IPA^(key): /kɔ̃/

con-

1. con-

Behaves as it does in English; see English usage notes.

From Latin con-, from cum (“with”).

• IPA^(key): [kɔ̃]

con-

1. con- (1)

• com-, qem-, qen-

• co-, com-

From Proto-Celtic *kom- (“with, together”), from Proto-Indo-European *ḱóm. Cognate with Old Irish com-, Welsh cyf-, Breton kev- or kem-.

con-

1. con- (1)

• co-
• com-

From Latin con-, from cum (“with”).

• IPA^(key): /kon/
• Hyphenation: con-

con-

1. con- (1)

From the preposition cum (“with”).

• (Classical) IPA^(key): /kon/, [kɔn]
• (modern Italianate Ecclesiastical) IPA^(key): /kon/, [kon]

con-

1. Used in compounds to indicate a being or bringing together of several objects

   coeō, colloquor, convīvor, etc.: colligō, compōnō, condō, etc.

2. Used in compounds to indicate the completeness, perfecting of any act, and thus gives intensity to the signification of the simple word

   commaculō, commendō, concitō, comminuō, concerpō, concīdō, convellō, etc.

• Before vowels and h, the prefix becomes co-, or rarely com-. Excluded are i and u when these represent /j/ and /w/.
• Before b, m and p, the prefix becomes com-.
• Before l, the prefix becomes col-.
• Before r, the prefix becomes cor-.
• Before n, the prefix becomes cō- (or remains con-, in Late Latin).
• Before original gn, the prefix becomes co- and gn is not reduced to n.

As usual in Latin phonology, the sequences ons and onf are pronounced with nasalised long vowels, and the vowel is written with a macron, i.e. cōnspīrō and cōnferō.

• “con-”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers

• com-

Borrowed from Old French con- and Latin con-.

• IPA^(key): /kɔn-/, /kun-/

con-

1. (non-productive) con- (with)

• This prefix frequently has reduced or no semantic force.

• English: con-
• Scots: con-

• “con-, cǒn-, pref.”, in MED Online, Ann Arbor, Mich.: University of Michigan, 2007.

• co-, com-

Inherited from Latin con-, from cum (“with”).

• IPA^(key): /kon/ [kõn]
• Syllabification: con-

con-

1. with

• Before the letters b or p use the form com-. Sometimes the co- form is used instead.

• “con-”, in Diccionario de la lengua española, Vigésima tercera edición, Real Academia Española, 2014