| Noun | 1. | cardinal - (Roman Catholic Church) one of a group of more than 100 prominent bishops in the Sacred College who advise the Pope and elect new PopesChurch of Rome, Roman Catholic Church, Roman Church, Western Church, Roman Catholic - the Christian Church based in the Vatican and presided over by a pope and an episcopal hierarchy College of Cardinals, Sacred College - (Roman Catholic Church) the body of cardinals who advise the Pope and elect new Popes bishop - a senior member of the Christian clergy having spiritual and administrative authority; appointed in Christian churches to oversee priests or ministers; considered in some churches to be successors of the twelve Apostles of Christ dean - (Roman Catholic Church) the head of the College of Cardinals |
| 2. | cardinal - the number of elements in a mathematical set; denotes a quantity but not the order number - a concept of quantity involving zero and units; "every number has a unique position in the sequence" absolute frequency, frequency - the number of observations in a given statistical category googol - a cardinal number represented as 1 followed by 100 zeros (ten raised to the power of a hundred) googolplex - a cardinal number represented as 1 followed by a googol of zeros (ten raised to the power of a googol) | |
| 3. | cardinal - a variable color averaging a vivid red | |
| 4. | cardinal - crested thick-billed North American finch having bright red plumage in the malefinch - any of numerous small songbirds with short stout bills adapted for crushing seeds genus Richmondena, Richmondena - cardinals | |
| Adj. | 1. | cardinal - serving as an essential component; "a cardinal rule"; "the central cause of the problem"; "an example that was fundamental to the argument"; "computers are fundamental to modern industrial structure" |
| 2. | cardinal - being or denoting a numerical quantity but not order; "cardinal numbers" ordinal - being or denoting a numerical order in a series; "ordinal numbers"; "held an ordinal rank of seventh" |