Tri-
From Wikipedia, the free encyclopedia
Look up tri- in Wiktionary, the free dictionary.
Tri- or tria- is a numerical prefix meaning 3 that can be either Greek or Latin; though occasionally tre- and ter- also exist for Latin. Examples are:
- A trioxide has 3 oxygen atoms
- A tricycle is a children's vehicle with 3 wheels
- A trilogy is a series of 3 plays or books
- The Triassic Period had 3 layers of rock.
- A triad has 3 musical notes.
"Tri-" is now a productive prefix in English, even for words that are not of immediate Latin or Greek origin:
- A trimonthly event occurs every three months.
- A tri-captain (U.S. only?) is one of three equal captains of a sports team.
Examples of the rare English "ter-" and "tre-" are:
- "tercentenary", a 300th anniversary.
- "ternary" (rather than trinary), the analogue of "binary"
- "tertiary"
- "treble"
- "trefoil"
The Sanskrit cognate "tri-" has been used as a prefix for unknown elements indicating that it is three rows below the nearest known element in the periodic table.
