noun- The ordinal number matching the number three in a series.
- One of three equal parts.
- Music
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:
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
thrīe, and
third was
thridda. Thridda would have given us
thrid in Modern English except for the metathesis of
r and
i. 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 (originally
bridd 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 from
thorp, “village,” which survives in the proper name
Winthrop.