18-letter words containing o, a, t, c
- chocolate-coloured — dark brown
- christian brothers — a religious congregation of laymen founded in France in 1684 for the education of the poor
- christian democrat — a member or supporter of a Christian Democratic party
- christian endeavor — an organization of young people of various evangelical Protestant churches, formed in 1881 to promote Christian principles and service.
- christian reformed — of or relating to a Protestant denomination (Christian Reformed Church) organized in the U.S. in 1857 by groups that had seceded from the Dutch Reformed Church.
- christmas shopping — shopping especially for Christmas presents, but also for Christmas food and drink, and all the other things required over the Christmas period.
- christmas stocking — A Christmas stocking is a long sock which children hang up on Christmas Eve. During the night, parents fill the stocking with small presents.
- chromatic printing — printing from blocks or types inked with various colours
- chromatic semitone — the pitch difference between one note and its sharpened or flattened equivalent
- chromolithographer — One engaged in chromolithography.
- chromolithographic — Pertaining to, or made by, chromolithography.
- chronostratigraphy — The branch of geology concerned with establishing the absolute ages of strata.
- church of scotland — the established church in Scotland, Calvinist in doctrine and Presbyterian in constitution
- cigar-store indian — a wooden statue of an American Indian, traditionally displayed at the entrance of cigar stores.
- circulatory system — the system concerned with the transport of blood and lymph, consisting of the heart, blood vessels, lymph vessels, etc
- circumnavigational — Relating to circumnavigation.
- citizen journalism — the involvement of non-professionals in reporting news, esp in blogs and other websites
- citta del vaticano — Vatican City
- classified section — the part of a publication that contains classified advertising
- claustrophobically — In a claustrophobic way.
- claw-and-ball foot — ball-and-claw foot.
- clean up one's act — to start to behave in a responsible manner
- cleopatra's needle — either of two Egyptian obelisks, originally set up at Heliopolis about 1500 bc: one was moved to the Thames Embankment, London, in 1878, the other to Central Park, New York, in 1880
- clinical pathology — the branch of pathology dealing with the study of disease and disease processes by means of chemical, microscopic, and serologic examinations.
- closed corporation — a corporation the stock of which is owned by a small number of persons and is rarely traded on the open market
- clothing allowance — an amount of money to compensate for the purchase of clothes for work, school, etc
- coals to newcastle — If someone is taking coals to Newcastle, they are trying to give or sell someone something that they already have a lot of.
- coast rhododendron — a rhododendron, Rhododendron macrophyllum, of western North America, having large clusters of rose-purple flowers spotted with brown: the state flower of Washington.
- coast-guard cutter — a cutter used by the U.S. Coast Guard.
- coastguard station — the headquarters or local offices of a coastguard
- cobalt violet deep — a medium to strong purple color.
- coffee-table music — unadventurous music
- collagen injection — an injection of collagen into the lip in order to give it a fuller appearance
- collection charges — the charges levied to cover expenses for the collection of debt
- collision diameter — the distance between the centers of two colliding molecules when at their closest point of approach.
- colloidal solution — a mixture having particles of one component, with diameters between 10 −7 and 10 −9 metres, suspended in a continuous phase of another component. The mixture has properties between those of a solution and a fine suspension
- colonic irrigation — Colonic irrigation is a medical procedure in which a person's colon is washed by injecting water or other fluids into it.
- color transparency — a positive color image photographically produced on transparent film or glass and viewed by transmitted light, usually by projection.
- colour commentator — a sports celebrity who works as part of a commentary team
- colour photography — the art or process of taking and developing photographs in colour
- colour temperature — the temperature of a black-body radiator at which it would emit radiation of the same chromaticity as the light under consideration
- combination square — an adjustable device for carpenters, used as a try square, miter square, level, etc.
- combined operation — a military operation carried out jointly by allied forces
- combustion chamber — an enclosed space in which combustion takes place, such as the space above the piston in the cylinder head of an internal-combustion engine or the chambers in a gas turbine or rocket engine in which fuel and oxidant burn
- combustion furnace — a furnace used in the laboratory to carry out elemental analysis of organic compounds
- come back to earth — to return to reality from a fantasy or daydream
- come the raw prawn — to attempt deception
- commando operation — a major operation for treatment of cancer of the head and neck, involving removal of many facial structures and subsequent surgical reconstruction
- commedia dell'arte — a form of popular comedy developed in Italy during the 16th to 18th centuries, with stock characters such as Punchinello, Harlequin, and Columbine, in situations improvised from a plot outline
- commendation medal — a U.S. military decoration awarded for meritorious achievement or service