- The ordinal number matching the number three in a series.
- One of three equal parts.
a. An interval of three degrees in a diatonic scale.
b. A tone separated by three degrees from a given tone, especially the third tone of a scale.
- The transmission gear or gear ratio used to produce forward speeds next higher to those of second in a motor vehicle.
- Baseball Third base.
- thirds Merchandise whose quality is below the standard set for seconds.
Origin: Middle English thridde, therdde, third
Origin: , from Old English thridda; see trei- in Indo-European roots
Related Forms:Word History:
Every native speaker knows that the cardinal three
and the ordinal third
are closely related, but many may wonder why the r
comes before the vowel in the former and after in the latter. What we have here is metathesis, the switching of the order of two sounds. This is a common occurrence in languages, and especially so in English with the consonant r.
In Old English, three
was thridda. Thridda
would have given us thrid
in Modern English except for the metathesis of r
This metathesis began in Old English times in Northumbria: thridda
appears as thirdda
in Northumbrian manuscripts. The metathesis spread south during Middle English times and also affected many other words, including bird
in Old English and in Chaucer's Middle English), and nostril,
literally “nose hole” (from Old English thyrl
). Metathesis even produced the curious form throp
“village,” which survives in the proper name Winthrop.