Register

noun
1.
a book in which records of acts, events, names, etc., are kept.
2.
a list or record of such acts, events, etc.
3.
an entry in such a book, record, or list.
4.
an official document issued to a merchant ship as evidence of its nationality.
5.
registration or registry.
6.
a mechanical device by which certain data are automatically recorded.
7.
cash register.
8.
Music.

the compass or range of a voice or an instrument.
a part of this range produced in the same way and having the same quality:
the head register; the upper register of the clarinet.
(in an organ) a stop.

9.
a device for controlling the flow of warmed air or the like through an opening, as from a duct to an interior, composed of a number of narrow, parallel blades, usually behind a grating, that may be adjusted so as to overlap and close the opening.
10.
Photography. proper relationship between two plane surfaces in photography, as corresponding plates in photoengraving.
11.
Printing.

a precise adjustment or correspondence, as of lines, columns, etc., especially on the two sides of a leaf.
correct relation or exact superimposition, as of colors in color printing.

12.
a bookmark, especially a ribbon attached to the spine of a book.
13.
Linguistics. a variety of language typically used in a specific type of communicative setting:
an informal register; the register of scientific discourse.
14.
Computers. a high-speed storage location in the CPU, used to store a related string of bits, as a word or phrase.
verb (used with object)
15.
to enter or cause to be entered formally in a register.
16.
to cause (mail) to be recorded upon delivery to a post office for safeguarding against loss, theft, damage, etc., during transmission.
17.
to enroll (a student, voter, etc.) in a school or course of study, on the voting rolls, etc.
18.
to indicate by a record, as instruments do:
The thermometer registered 102 degrees today.
19.
to indicate or show, as on a scale.
20.
Printing. to adjust so as to secure exact correspondence; cause to be in register.
21.
Military. to adjust (fire) on a known point.
22.
to show (surprise, joy, anger, etc.), as by facial expression or by actions.
23.
to document (a merchant ship engaged in foreign trade) by issuing a certificate of registry.
verb (used without object)
24.
to enter one’s name or cause it to be entered in a register; enroll:
to register at a motel.
25.
to apply for and obtain inclusion of one’s name on the list of voters.
26.
to enroll in a school or course of study:
I’ve registered for three English classes.
27.
Printing. to be in register.
28.
to show:
A broad smile registered on his face.
29.
to have some effect; make some impression:
My plea didn’t register on him at all.
noun
1.
an official or formal list recording names, events, or transactions
2.
the book in which such a list is written
3.
an entry in such a list
4.
a recording device that accumulates data, totals sums of money, etc: a cash register
5.
a movable plate that controls the flow of air into a furnace, chimney, room, etc
6.
(computing) one of a set of word-sized locations in the central processing unit in which items of data are placed temporarily before they are operated on by program instructions
7.
(music)

the timbre characteristic of a certain manner of voice production See head voice, chest voice
any of the stops on an organ as classified in respect of its tonal quality: the flute register

8.
(printing)

the correct alignment of the separate plates in colour printing
the exact correspondence of lines of type, columns, etc, on the two sides of a printed sheet of paper

9.
a form of a language associated with a particular social situation or subject matter, such as obscene slang, legal language, or journalese
10.
the act or an instance of registering
verb
11.
(transitive) to enter or cause someone to enter (an event, person’s name, ownership, etc) on a register; formally record
12.
to show or be shown on a scale or other measuring instrument: the current didn’t register on the meter
13.
to show or be shown in a person’s face, bearing, etc: his face registered surprise
14.
(intransitive) to have an effect; make an impression: the news of her uncle’s death just did not register
15.
to send (a letter, package, etc) by registered post
16.
(transitive) (printing) to adjust (a printing press, forme, etc) to ensure that the printed matter is in register
17.
(intransitive) often foll by with. (of a mechanical part) to align (with another part)
18.
(military) to bring (a gun) to bear on its target by adjustment according to the accuracy of observed single rounds
register

1. One of a small number of high-speed memory locations in a computer’s CPU. Registers differ from ordinary random-access memory in several respects:
There are only a small number of registers (the “register set”), typically 32 in a modern processor though some, e.g. SPARC, have as many as 144. A register may be directly addressed with a few bits. In contrast, there are usually millions of words of main memory (RAM), requiring at least twenty bits to specify a memory location. Main memory locations are often specified indirectly, using an indirect addressing mode where the actual memory address is held in a register.
Registers are fast; typically, two registers can be read and a third written — all in a single cycle. Memory is slower; a single access can require several cycles.
The limited size and high speed of the register set makes it one of the critical resources in most computer architectures. Register allocation, typically one phase of the back-end, controls the use of registers by a compiled program.
See also accumulator, FUBAR, orthogonal, register dancing, register allocation, register spilling.
2. An addressable location in a memory-mapped peripheral device. E.g. the transmit data register in a UART.