Browse Dictionary by Letter

Dictionary Suite
A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z
ionosphere layers of the earth's atmosphere located above the stratosphere from about thirty to two hundred and fifty miles above the earth's surface, and composed of rarefied gases that have been ionized by radiation from the sun.
iota the name of the ninth letter of the Greek alphabet. [2 definitions]
IOU a signed paper acknowledging a debt and often bearing these letters, meaning "I owe you".
-ious full of; having the characteristics of; having.
Iowa a Midwestern U.S. state between Illinois and Nebraska. (abbr.: IA) [3 definitions]
IP in computing, an abbreviation for Internet protocol, one of the main Internet communications protocols, which specifies the format of transmitted data and routing information.
ipecac either of two tropical South American plants related to madder, coffee, and gardenia, whose roots are used medicinally. [2 definitions]
iPod trademark for a pocket-sized digital audio player with a large storage capacity, primarily used to collect and play back downloaded digital music files.
ipomoea a plant of the morning glory family that has heart-shaped leaves and bears showy flowers. [2 definitions]
ipse dixit he himself said it (Latin); an unproven or dogmatic assertion.
ipso facto by that fact itself.
IQ abbreviation of "intelligence quotient," a representation of mental age as determined by intelligence tests.
Ir symbol of the chemical element iridium.
ir-1 in; into. [2 definitions]
ir-2 not; without.
IRA abbreviation of "Individual Retirement Account."
I.R.A. abbreviation of "Irish Republican Army."
Iran a Middle Eastern country between Turkmenistan, the Caspian Sea, and the Persian Gulf.
Iranian of or pertaining to Iran or its people, culture, or the like; Persian. [4 definitions]
Iraq a Middle Eastern country between Syria and Iran.
Iraqi a native or citizen of Iraq, or a descendant thereof. [3 definitions]