angstrom

¹ American  

[ang-struhm] / ˈæŋ strəm /

noun

(often initial capital letter)

1. a unit of length, equal to one tenth of a millimicron, or one ten millionth of a millimeter, primarily used to express electromagnetic wavelengths. Å; A

---

Ångström ² American  

[ang-struhm, awng-strœm] / ˈæŋ strəm, ˈɔŋ strœm /

noun

1. Anders Jonas 1814–74, Swedish astronomer and physicist.

---

Ångström ¹ British  

/ ˈæŋstrəm, ˈɔŋstrœm /

noun

1. Anders Jonas (ˈandərs ˈjuːnas). 1814–74, Swedish physicist, noted for his work on spectroscopy and solar physics

---

angstrom ² British  

/ ˈæŋstrʌm, -strəm /

noun

1.  Å.   A.  Also called: angstrom unit.  a unit of length equal to 10 ^–10 metre, used principally to express the wavelengths of electromagnetic radiations. It is equivalent to 0.1 nanometre

---

Ångström ¹ Scientific  

/ ăng′strəm /

1. Swedish physicist and astronomer who pioneered the use of the spectroscope in the analysis of radiation. By studying the spectrum of visible light given off by the Sun, Ångström discovered that there is hydrogen in the Sun's atmosphere. The angstrom unit of measurement is named for him.

---

angstrom ² Scientific  

/ ăng′strəm /

1. A unit of length equal to one hundred-millionth (10 ^{- 10}) of a meter. It was once used to measure wavelengths of light and the diameters of atoms, but has now been mostly replaced by the nanometer.

---

Etymology

Origin of angstrom

First recorded in 1895–1900; named after A. J. Ångström ( def. )

Example Sentences

The channels are built from proteins and contain extremely narrow regions at the angstrom scale.

From Science Daily • Feb. 19, 2026

Note: The length unit angstrom, Å, is often used to represent atomic-scale dimensions and is equivalent to 10−10 m.

From Textbooks • Feb. 14, 2019

One angstrom is 10–10 m or 0.0000000001 m.

From Textbooks • Jan. 1, 2015

Use your normal speaking voice—don't speak slowly or strain to over-pronounce "angstrom."

From Slate • Apr. 6, 2011

"In our own stellar system, the average shift is only a fraction of one angstrom."

From Time Magazine Archive