the number equivalent to the product of three and ten; ten less than forty; 30:thirty or forty years agothirty were hurtthirty of her school friends (Roman numeral: xxx or XXX)
(thirties) the numbers from thirty to thirty-nine, especially the years of a century or of a person’s life:a woman in her thirtiesshe was a famous actress in the thirties
thirty years old:I’ve got a long way to go before I’m thirty
thirty miles an hour:doing about thirty
a size of garment or other merchandise denoted by thirty.
Derivatives
thirtieth
number
thirtyfold
adjective & adverb
Origin:
Old Englishthrītig(see three, -ty2). The spelling with initial thi- is recorded in literature in the 15th century, and has been the prevalent form since the 16th century
