infra-

/ˈin-frə How to pronounce infra (audio) also -ˌfrä/ (ame, mw)

infra- — prefix

1. added to the start of a scientific or medical word to show that something is bel

1.字首B2
釋義

added to the start of a scientific or medical word to show that something is below, beneath, or lower than another part, band, or level.

例句

Bilal used an infrared camera to check for heat leaks in the attic.

infrared = below the red end of light

The scan showed swelling near Manuela's infraorbital nerve after the fall.

infraorbital = below the eye socket

同義詞
  • sub-

    the more common technical prefix for something under or lower in rank, place, or structure

  • under-

    the everyday English form, used much more freely outside technical compounds

反義詞
  • supra-

    formal opposite prefix meaning above or beyond in paired technical terms

  • super-

    broader and more common prefix for above, over, or higher

文法句型

infra- + anatomy term (infraorbital, infrarenal)

infra- + science term (infrared, infrasonic)

用法筆記

Mostly appears in learned compounds from science, medicine, and formal technical writing, such as infrared, infrasonic, and infraorbital. In everyday English, people normally say 'below' or 'under' instead of using infra- as a separate word. It often contrasts with supra- in paired technical terms.

常見錯誤

❌The ladder is infra the shelf.
✅The ladder is below the shelf.
💡infra- is a prefix inside technical compounds, not a free-standing everyday word.
❌The clinic bought an infra red camera.
✅The clinic bought an infrared camera.
💡many established compounds with infra- are written as one word.