tri-, tre-

(Greek > Latin: a numerical prefix meaning, three, thrice, threefold; triple; a word element for number 3)

trifarious (adjective) (not comparable)
1. Relating to three sorts or facing that many ways.
2. Characteristic of groups which consist of triple kinds or rows.
trifecta
1. A bet, especially on a horserace, that involves selecting the competitors that will come in the first three places in the correct order.
2. A situation in which three major accomplishments, results, or achievements take place in a sport, a profession, in politics, or an interest or activity done during one's spare time..
3. A series or set of three things, factors, or influences; such as, a trifecta of political results.

I grant that estimates about jobs and revenue are uncertain. But they are not meaningless, and the strong implication is that Republican rule would lead to the Trifecta of Torment: higher unemployment, worse deficits, and greater inequity.

—A quote from "Trifecta of torment" by Nicholas D. Kristof;
"The Global Edition" of the New York Times, as seen in The International Herald Tribune;
Friday, October 8, 2010; page 9.
trifid
Split into three.
trifocal (noun), trifocals (pl)
1. Having three focal lengths.
2. Having one section that corrects for distant vision, a second section that corrects for medium vision, and a third that corrects for near vision; such as, an eyeglass lens.
trifoliate, trifoliated, trifoliolate
Having three leaves or leaflets.
trifoliosis
A form of photosensitization that occurs in horses, cattle, sheep, and pigs from eating several types of clover and alfalfa.
triforium
A gallery between the vaulting and the roof of the aisle of a church; so called because it often has three openings to each bay.
trifurcate (TRIGH fuhr kayt") (verb), trifurcates; trifurcated, trifurcating
To divide into three parts or sections: Branching off or parting into three directions: While following the map, Bernice could see that the freeway trifurcated in about three miles, but she knew she needed to stay in the middle lane because she did not want to travel in the right or the left lanes.
trigamist
A person who has three spouses simultaneously.
trigamous
1. The state of having three wives or husbands at the same time.
2. The crime of contracting a third marriage while two previous spouses are alive.
3. Marriage for the third time after the death of former wives or husbands.
trigamy
A reference to someone who has three spouses simultaneously.
trigeminal, trigeminus
Triple; pertaining to the fifth cranial nerve (nervus trigeminus); called the fifth pair of cranial nerves because of their division into three branches; also called 'trifacial'.
trigeminy
The condition of occurring in threes, especially the occurrence of three pulse beats in rapid succession.
trigenarian
1. A person who is in her/his thirties.
2. Someone who is from thirty to thirty-nine years old.
trigenetic
In biology, pertaining to a symbiont requiring three different hosts during its life cycle.

Cross references of word families that are related, partially or totally, to: "three, third": terce-; terti-; trigono-; trito-.