angstrom

UK: /ˈæŋstrʌm/ US: (ang′strəm)

WordReference Random House Unabridged Dictionary of American English © 2025

ang•strom  (ang′strəm), n. (often cap.)

1. Physics, Weights and Measures a unit of length, equal to one tenth of a millimicron, or one ten millionth of a millimeter, primarily used to express electromagnetic wavelengths. Symbol: Å;
   Abbr.: A  Also called ang′strom u′nit, Ang′strom u′nit. 

• named after A. J. Ångström 1895–1900

Ång•ström  (ang′strəm; Swed. ông′strœm), n. An•ders Jo•nas 

(an′dərz jō′nəs; Swed. än′dərs yo̅o̅′näs), 
1. 1814–74, Swedish astronomer and physicist.

Collins Concise English Dictionary © HarperCollins Publishers::

angstrom / ˈæŋstrʌm -strəm/ noun

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

Etymology: 20th Century: named after Anders J. Ångström