register

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A formal or official recording of items, names, or actions.
• noun A book for such entries.
• noun An entry in such a record.
• noun The act of registering.
• noun A device that automatically records a quantity or number.
• noun Computers A part of the central processing unit used as a storage location.
• noun An adjustable, grill-like device through which heated or cooled air is released into a room.
• noun A state of proper alignment.
• noun Exact alignment of the lines and margins on the opposite sides of a leaf.
• noun Proper positioning of colors in color printing.
• noun The range of an instrument or a voice.
• noun A part of such a range.
• noun A group of matched organ pipes; a stop.
• noun A variety or level of language used in a specific social setting.
• intransitive verb To enter in an official register.
• intransitive verb To enroll officially or formally, especially in order to vote or attend classes.
• intransitive verb To set down in writing.
• intransitive verb To express or make known.
• intransitive verb To indicate (data). Used of an instrument or scale.
• intransitive verb To be indicated as.
• intransitive verb To give outward signs of; express.
• intransitive verb To attain or achieve.
• intransitive verb To cause (mail) to be officially recorded and specially handled by payment of a fee.
• intransitive verb To adjust so as to be properly aligned.
• intransitive verb To place or cause placement of one's name in a register.
• intransitive verb To have one's name officially placed on a list of eligible voters.
• intransitive verb To enroll as a student.
• intransitive verb To have a list of gifts for preferred wedding presents, as at a store. Used of a couple.
• intransitive verb To be indicated on an instrument or a scale.
• intransitive verb To be shown or expressed, as on the face.
• intransitive verb To make an impression; be recorded in the mind.
• intransitive verb To be in proper alignment.

from The Century Dictionary.

• To enter (a letter) at a post-office as a registered letter (which see, under letter).
• noun An official written account or entry, usually in a book regularly kept, as of acts, proceedings, or names, for preservation or for reference; a record; a list: a roll; also, the book in which such a record is kept: as, a parish register; a hotel register.
• noun In com., a document issued by the customs authorities as evidence of a ship's nationality. See registration of British ships, under registration.
• noun The printed list of signatures at the end of early printed books.
• noun In music: The compass or range of a voice or an instrument.
• noun A particular series of tones, within the compass of a voice or of certain instruments, which is produced in the same way and with the same quality: as, the chest-register of the voice, or the chalumeau register of the clarinet.
• noun In organ-building: Same as stop or stop-knob.
• noun A perforated frame or board for holding a set of trackers in place.
• noun A device for registering automatically the number of revolutions made or the amount of work done by machinery, or for recording the pressure of steam, air, or water, or other data, by means of apparatus deriving motion from the object or objects whose force, velocity, etc., it is desired to ascertain.
• noun A contrivance for regulating the passage of heat or air, as the draft-regulating plate of a furnace, or the damper-plate of a locomotive engine; a perforated plate with valves governing the opening into a duct which admits warm air into a room for heat, or fresh air for ventilation, or which allows foul air to escape.
• noun In printing, exact adjustment of position in the presswork of books or papers printed on both sides of the leaf.
• noun The inner part of the mold in which types are cast.