keys

1. An object designed to open and close a lock.
2. An object designed to fit between two other objects (such as a shaft and a wheel) in a mechanism and maintain their relative orientation.
3. A crucial step or requirement.

   The key to solving this problem is persistence.

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

   The key says that A stands for the accounting department.

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

   Some students cheated by using the answer key.

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

   Press the Escape key.

7. In musical instruments, one of the valve levers used to select notes, such as a lever opening a hole on a woodwind.
8. 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.
9. The lowest note of a scale; keynote.
10. In musical theory, the total melodic and harmonic relations, which exist between the tones of an ideal scale, major or minor; tonality.
11. 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.
12. In musical notation, a sign at the head of a staff indicating the musical key.
13. The general pitch or tone of a sentence or utterance.
14. A modification of an advertisement so as to target a particular group or demographic.
15. An indehiscent, one-seeded fruit furnished with a wing, such as the fruit of the ash and maple; a samara.
16. A manual electrical switching device primarily used for the transmission of Morse code.
17. A piece of information (e.g. a passphrase) used to encode or decode a message or messages.
18. A password restricting access to an IRC channel.
19. In a relational database, a field used as an index into another table (not necessarily unique).
20. A value that uniquely identifies an entry in a container.
21. 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.

    He shoots from the top of the key.

22. A series of logically organized groups of discriminating information which aims to allow the user to correctly identify a taxon.
23. A piece of wood used as a wedge.
24. The last board of a floor when laid down.
25. A keystone.
26. That part of the plastering which is forced through between the laths and holds the rest in place.
27. A wooden support for a rail on the bullhead rail system.
28. The degree of roughness, or retention ability of a surface to have applied a liquid such as paint, or glue.

    The door panel should be sanded down carefully to provide a good key for the new paint.

29. The thirty-third card of the Lenormand deck.
30. (print and film) The black ink layer, especially in relation to the three color layers of cyan, magenta, and yellow. See also CMYK.
31. A color to be masked or made transparent.

1. To fit (a lock) with a key.
2. To fit (pieces of a mechanical assembly) with a key to maintain the orientation between them.
3. To mark or indicate with a symbol indicating membership in a class.
4. (telegraphy and radio telegraphy) To depress (a telegraph key).
5. To operate (the transmitter switch of a two-way radio).
6. (more usually to key in) To enter (information) by typing on a keyboard or keypad.

   Our instructor told us to key in our user IDs.

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

   He keyed the car that had taken his parking spot.

8. To link (as one might do with a key or legend).
9. To be identified as a certain taxon when using a key.
10. To modify (an advertisement) so as to target a particular group or demographic.
11. To attune to; to set at; to pitch.
12. To fasten or secure firmly; to fasten or tighten with keys or wedges.

1. One of a string of small islands.

   the Florida Keys

1. In the International System of Units, the base unit of mass; conceived of as the mass of one litre of water, but now defined by taking the fixed numerical value of the Planck constant h to be 6.626 070 15 × 10-34 when expressed in units of kg⋅m2⋅s−1. Symbol: kg
2. The unit of weight such that a one-kilogram mass is also a one-kilogram weight.

noun

A stone or concrete structure on navigable water used for loading and unloading vessels; a wharf.