co-

From Latin co-.

• enPR: kōʹ, IPA^(key): /ˈkoʊ-/
• (unstressed) enPR: kŏ, IPA^(key): /kɒ/

co-

1. together; mutually; jointly
2. partner or subordinate in an activity
3. to the same degree
4. (mathematics) of the opposite, of the counterpart; dual

   cokernel; codimension; cosine; counion; cointersection

• With many terms, a hyphen (-) is used in British English (e.g. co-operate), which is omitted in informal American English (e.g. cooperate). In formal American English the second vowel would be decorated with a diaeresis (coöperate), although this usage is rare and somewhat fussy.

• cosemisimple
• coseparable
• cosplit
• counital

• O. C., O.C., OC, Oc, Oc.

From Latin co-.

co-

1. co- (together; jointly)

• “co-” in Diccionari de la llengua catalana, segona edició, Institut d’Estudis Catalans.
• “co-” in Gran Diccionari de la Llengua Catalana, Grup Enciclopèdia Catalana.
• “co-” in Diccionari normatiu valencià, Acadèmia Valenciana de la Llengua.

• IPA^(key): /ko/, /kɔ/

co-

1. co- (together; jointly)

Shortened form of cum, from Old Latin com, from Proto-Italic *kom, from Proto-Indo-European *ḱóm (“next to, at, with, along”), cognate with Proto-Germanic *ga- (“co-”).

co-

1. together, with

   cōgō, Quirīnus (co-vir-īnus), cohaereō, coeō

2. (intensifier)
   • orior (“I rise”) → coorior (“I arise, I spring forth”)
   • emō (“I buy”) → coemō (“I buy up”)
   • rumpō (“I break, I destroy”) → corrumpō (“I pervert, I contaminate”)
   • horrēscō (“I dread”) → cohorrēscō (“I shudder, I shiver”)
   • lābor (“I slip, I go wrong”) → collābor (“I collapse, I fall in ruin”)

• com-
• con-

From Old Irish com-.

co-

1. co-

• “com-” in Dictionary of the Irish Language, Royal Irish Academy, 1913–76.

• IPA^(key): /t͡sɔ/

co-

1. Forms adjectives specifying how often something happens; -ly

   codzienny ― daily

   cogodzinny ― hourly

   comiesięczny ― monthly

   coroczny ― yearly

• co- in Polish dictionaries at PWN

• comh-

From Old Irish com-.

co-

1. Usually (but not always) designates mutuality or reciprocity.

• “com-” in Dictionary of the Irish Language, Royal Irish Academy, 1913–76.

From Latin co-.

co-

1. co-

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