Meanings
nouncysteine (countable and uncountable, plural cysteines)
plural cysteines
- countableuncountablebiochemistryA sulphur-containing nonessential amino acid C₃H₇NO₂S found in most animal proteins; it readily oxidizes to cystine.
Synonyms: E910 when used as a food additive, E920 when used as an improving agent, Cys when viewed as a monomer in proteins
Synonyms & antonyms
nounA sulphur-containing nonessential amino acid C₃H₇NO₂S found in most animal proteins; it readily oxidizes to cystine.
Similar
E910 when used as a food additiveE920 when used as an improving agentCys when viewed as a monomer in proteins
Origin
An alteration of cystine, see -eine.
Full word history & related roots →Translations
Bulgarian цистеин
- цистеин (cistein)nonessential amino acid
Catalan cisteïna
- cisteïnanonessential amino acid
Chinese Mandarin 半胱氨酸
- 半胱氨酸 (bànguāng'ānsuān)nonessential amino acid
Czech cystein
- cysteinnonessential amino acid
Danish cystein
- cysteinnonessential amino acid
Esperanto cisteino
- cisteinononessential amino acid
Finnish kysteiini
- kysteiininonessential amino acid
French cystéine
- cystéinenonessential amino acid
German Cystein
- Cysteinnonessential amino acid
Greek κυστεΐνη
- κυστεΐνη (kysteḯni)nonessential amino acid
Hungarian cisztein
- ciszteinnonessential amino acid
Indonesian sistein
- sisteinnonessential amino acid
Italian cisteina
- cisteinanonessential amino acid
Japanese システイン
- システイン (shisutein)nonessential amino acid
Korean 시스테인
- 시스테인 (siseutein)nonessential amino acid
Persian سیستئین
- سیستئین (siste'in)nonessential amino acid
Polish cysteina
- cysteinanonessential amino acid
Portuguese cisteína
- cisteínanonessential amino acid
Romanian cisteină
- cisteinănonessential amino acid
Russian цистеи́н
- цистеи́н (cisteín)nonessential amino acid
Spanish cisteína
- cisteínanonessential amino acid
Swedish cystein
- cysteinnonessential amino acid
Rhymes & wordplay
Rhymes with cysteine
All rhymes →Cite this entry
APA
cysteine. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/cysteine
MLA
“cysteine.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/cysteine. Accessed November 3, 2026.
Chicago
WatkinsX Dictionary, s.v. “cysteine,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/cysteine.
Source: cysteine on Wiktionary, CC BY-SA 4.0.