third hand
Having been relayed by two intermediate sources.
I heard the story from someone who got it from the horse's mouth. You're getting it third hand.
ADJ
first, middle, last
During the first third of the movie, the main character discovers an important secret.
bottom, lower
top, upper
The top third of the mountain was covered in thick snow throughout winter.
VERB + THIRD
divide sth into
The recipe says to divide the flour into thirds before adding each portion.
PREP
~ of
About a third of the students in my class walk to school every day.
PHRASES
about/almost/at least/over a third, between a third and a half, a third to (a) half
About a third of the students in my class walk to school every day.