tri-

Tri- is a combining form used like a prefix meaning “three.” Tri- is often used in a great variety of both everyday and technical terms.

Tri- ultimately comes from both Greek �ٰ���î��, �ٰ�í�� and Latin �ٰ�ŧ��, tria, all of which mean “three.”

An example of a word you may have encountered that features tri- is trident, “a three-pronged instrument or weapon.” The word trident comes from Latin �ٰ�����ŧ�Բ�, which uses the equivalent of the form tri- in the language.

The tri- part of the word means “three,” while the -dent part means “tooth.” Trident literally translates to “three teeth” or “three-toothed.”

Tri- also features in common words such as triangle and tricycle. Learn more about the origins of these words at their entries.

������ are some words that use the combining form tri-?

• triaxial
• �ٰ����徱����Բ����DzԲ�����
• tridymite (using the equivalent form of tri- in Greek)
• triethyl
• trifacial
• trifocal
• trifold
• trigram
• trihedral
• trihydrate
• trihydroxy

The following words use the equivalent forms of tri- in Latin or Greek:

• triad
• triarchy
• triceps
• tridactyl
• tridentate
• triduum
• triennial
• trifolium
• triform
• trigamy
• triglyph
• trigone
• trimeter
• triplex
• tripod
• tritoma

������ are some other forms that tri- may be commonly confused with?

• tetr-
• tor-
• tricho-
• trinitro-
• tris-
• -trix
• twi-

Not every word that begins with the letters tri- is necessarily using the combining form tri- to denote “three.” Learn why triage literally means “sorting” at our entry for the word.

Tripods are stands used for holding cameras and telescopes in place. The combining form -pod refers to  “foot.” With this in mind, what does tripod literally mean?