# tera- [TE ruh]

#### (Greek: "monster, marvel"; a decimal prefix used in the international metric system for measurements)

Used in the metric [decimal] system as one trillion [U.S.] and billionfold [U.K.]: 1012 [1 000 000 000 000] or a million million. The metric symbol for tera- is T.

According to the Academic Press Dictionary of Science and Technology, Harcourt Brace Jovanovich, Publishers, 1992: Tera- comes "from a Greek term meaning 'marvel' or 'monster,' with the sense that this is a huge and marvelous quantity." Oh, PLEASE!

It would make much more sense to have tera based on tetra- (Greek), "four" rather then terato-, "monster, marvel"; which has no relative connection with this or any other metric unit.

terabit
One trillion bits (eight bits make a byte, the common measure of memory or storage capacity). The word "bit" is a blend of binary and digit.
terabyte
A unit of information of one trillion bytes.
teracurie
One trillion curies. A curie is a unit of radioactivity equal to 3.7 times ten to the tenth power disintegrations per second.
teracycle
One trillion cycles (complete processes or sequences of pocesses in a machine or electronic device, or the time that this takes).
teraflop
One trillion floating-point operations per second; a measure of computer speed.
terahertz
A unit of frequency equal to one trillion hertz.
teraohm
A unit of electrical resistance, equal to one trillion ohms, or 1 000 000 megaohms.
teraohmmeter
An ohmmeter having a teraohm range for measuring extremely high insulation resistance values.
terapascal
One trillion pascals (units of pressure or stresses equal to one newton per square meter).
terasecond
One trillion seconds.
teravolt
One trillion volts.
terawatt
A unit of power, equal to one trillion watts, or 1 000 000 megawatts.

Related "metric" families: yotta; zetta; exa; peta; giga; mega; kilo; hecto; deka; deci; centi; milli; micro; nano; pico; femto; atto; zepto; yocto.