code vs key

code

noun
  • A cryptographic system using a codebook that converts words or phrases into codewords. 

  • By synecdoche: a codeword, code point, an encoded representation of a character, symbol, or other entity. 

  • A message represented by rules intended to conceal its meaning. 

  • Any system of principles, rules or regulations relating to one subject. 

  • A program. 

  • A particular lect or language variety. 

  • A set of unwritten rules that bind a social group. 

  • Instructions for a computer, written in a programming language; the input of a translator, an interpreter or a browser, namely: source code, machine code, bytecode. 

  • A short symbol, often with little relation to the item it represents. 

  • A body of law, sanctioned by legislation, in which the rules of law to be specifically applied by the courts are set forth in systematic form; a compilation of laws by public authority; a digest. 

  • An emergency requiring situation-trained members of the staff. 

  • A set of rules for converting information into another form or representation. 

verb
  • To encode. 

  • To call a hospital emergency code. 

  • To categorise by assigning identifiers from a schedule, for example CPT coding for medical insurance purposes. 

  • To go into a state where a hospital emergency code is required to save one's life. 

  • To encode a protein. 

  • To add codes to a dataset. 

  • Of a patient, to suffer a sudden medical emergency (a code blue) such as cardiac arrest. 

  • To write software programs. 

key

noun
  • A piece of information (e.g., a password or passphrase) used to encode or decode a message or messages. 

  • The general pitch or tone of a sentence or utterance. 

  • A piece of wood used as a wedge. 

  • A modification of an advertisement so as to target a particular group or demographic. 

  • One of several small, usually square buttons on a typewriter or computer keyboard, mostly corresponding to text characters. 

  • A scale or group of pitches constituting the basis of a musical composition. 

  • A series of logically organized groups of discriminating information which aims to allow the user to correctly identify a taxon. 

  • The degree of roughness, or retention ability of a surface to have applied a liquid such as paint, or glue. 

  • One of a string of small islands. 

  • A crucial step or requirement. 

  • A password restricting access to an IRC channel. 

  • In instruments with a keyboard such as an organ or piano, one of the levers, or especially the exposed front end of it, which are depressed to cause a particular sound or note to be produced. 

  • In musical notation, a sign at the head of a staff indicating the musical key. 

  • A value that uniquely identifies an entry in a container. 

  • A keystone. 

  • The last board of a floor when laid down. 

  • The lowest note of a scale; keynote. 

  • A wooden support for a rail on the bullhead rail system. 

  • In musical theory, the total melodic and harmonic relations, which exist between the tones of an ideal scale, major or minor; tonality. 

  • An indehiscent, one-seeded fruit furnished with a wing, such as the fruit of the ash and maple; a samara. 

  • In musical instruments, one of the valve levers used to select notes, such as a lever opening a hole on a woodwind. 

  • A guide to the correct answers of a worksheet or test. 

  • The thirty-third card of the Lenormand deck. 

  • A guide explaining the symbols or terminology of a map or chart; a legend. 

  • That part of the plastering which is forced through between the laths and holds the rest in place. 

  • In musical theory and notation, the tonality centering in a given tone, or the several tones taken collectively, of a given scale, major or minor. 

  • A manual electrical switching device primarily used for the transmission of Morse code. 

  • The black ink layer, especially in relation to the three color layers of cyan, magenta, and yellow. See also CMYK. 

  • The free-throw lane together with the circle surrounding the free-throw line, the free-throw lane having formerly been narrower, giving the area the shape of a skeleton key hole. 

  • A color to be masked or made transparent. 

  • An object designed to open and close a lock. 

  • In a relational database, a field used as an index into another table (not necessarily unique). 

  • An object designed to fit between two other objects (such as a shaft and a wheel) in a mechanism and maintain their relative orientation. 

verb
  • To be identified as a certain taxon when using a key. 

  • (more usually to key in) To enter (information) by typing on a keyboard or keypad. 

  • To fasten or secure firmly; to fasten or tighten with keys or wedges. 

  • To link (as one might do with a key or legend). 

  • To depress (a telegraph key). 

  • To prepare for plastering by adding the key (that part of the plastering which is forced through between the laths and holds the rest in place). 

  • To attune to; to set at; to pitch. 

  • To vandalize (a car, etc.) by scratching with an implement such as a key. 

  • To operate (the transmitter switch of a two-way radio). 

  • To modify (an advertisement) so as to target a particular group or demographic. 

  • To fit (pieces of a mechanical assembly) with a key to maintain the orientation between them. 

  • To mark or indicate with a symbol indicating membership in a class. 

  • To fit (a lock) with a key. 

adj
  • Important, salient. 

  • Indispensable, supremely important. 

How often have the words code and key occurred in a corpus of books? (source: Google Ngram Viewer )