Tri

Part of speech: prefix, noun

Pronunciation: /tɹaɪ/

Definitions

1. Indicating a grouping or quantity of three elements or units
2. Relating to a structure or concept divided into three parts or aspects
3. Describing something characterized by threesomeness, often seen in geometry or other fields

Etymology: The prefix "tri-" comes from Latin "tres" (three) and Greek "treis," which share an Indo-European ancestry, and it entered English as a combining element in words borrowed from Latin and Greek, such as "triangle" and "trilogy." Its meaning is simple: it marks a count of three, so a "tricycle" has three wheels and a "triad" is a group of three. Its use as a standalone noun is a shortening, a clipped form of longer words that begin with this component, such as "triathlon" or "trimester," so the short form took on a life of its own as a free-standing element. Because it is a combining form rather than an independent English word, its history is mostly the history of the words it appears in. Scientists and scholars drew on Greek and Latin roots to coin many new terms, and "tri-" became one of the most productive building blocks in that process, which is why it turns up so often in geometry, chemistry, and everyday compounds alike.

Synonyms: three, triple

Antonyms: mono, uni