half-hour

• half hour, halfhour

From half- +‎ hour.

half-hour (plural half-hours)

1. A period of time equal to thirty minutes, half an hour.
2. The time of thirty minutes past any particular hour.
   • 1807, [Miss Guion], chapter V, in The Three Germans. Mysteries Exemplified in the Life of Holstein of Lutztein. A German Romance. […], volume I, London: […] J[ames] F[letcher] Hughes, […], →OCLC, page 121:

     The great clock of the castle sounded the half-hour—he had another half-hour to wait, ere the approach of Count Deckendorff; […]

     Used in both senses.

   • 2024 May 8, Dhruv Tikekar, “How India got stuck in its own unusual time zone”, in CNN‎^[1]:

     India’s half-hour zone dates back to colonial rule of India and the era when ever-faster steamships and trains were shrinking the world.

• (a thirty minute period of time): half an hour