iso-

• is- (before a vowel)

Internationalism. Learned borrowing from Ancient Greek ἴσος (ísos, “equal”).

• (Received Pronunciation) IPA^(key): /aɪsə-/, /aɪsəʊ-/, /aɪˈsɒ-/
• (General American) IPA^(key): /aɪsə-/, /aɪsoʊ-/, /aɪˈsɑ-/, /aɪˈsɔ-/

• Audio (US):

  (file)

• Hyphenation: i‧so-

iso-

1. Same, identical.

   Synonyms: ipsi-, homo-, syn- / sym-

   Antonyms: hetero-, allo-

   ‎iso- + ‎effect → ‎isoeffect

   ‎iso- + ‎intense → ‎isointense

2. Equal; equivalent.

   Synonyms: equi-, pari-

   Antonym: aniso-

   ‎iso- + ‎rhythm → ‎isorhythm

3. (chemistry) Isomer.

   ‎iso- + ‎methadone → ‎isomethadone

4. (organic chemistry) Of an aliphatic compound, especially a fatty acid, having a branch on the penultimate carbon atom of a chain.

   ‎iso- + ‎hexane → ‎isohexane

5. (meteorology, geography) Forms terms for specific kinds of isolines.

   ‎iso- + ‎-therm → ‎isotherm

   ‎iso- + ‎-chrone → ‎isochrone

6. (mathematics) Isomorphism.

• homeo-

• “iso-”, in Collins English Dictionary, 2011–present.
• “iso-”, in Merriam-Webster.com Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.
• “iso-”, in OneLook Dictionary Search.
• “iso-, comb. form”, in OED Online ⁠, Oxford: Oxford University Press, launched 2000.

• I/Os, ios, OSI, SIO, soi, OIs, OIS, SOI, iOS, IOs, Ios

Internationalism. Learned borrowing from Ancient Greek ἴσος (ísos, “equal”).

iso-

1. iso-

Internationalism; ultimately from Ancient Greek ἴσος (ísos, “equal”).

• IPA^(key): /ˈiso-/, [ˈis̠o̞-]

iso-

1. (sciences, chemistry) iso-

• iso

• “2. iso-”, in Kielitoimiston sanakirja [Dictionary of Contemporary Finnish]‎^[1] (in Finnish) (online dictionary, continuously updated), Kotimaisten kielten keskuksen verkkojulkaisuja 35, Helsinki: Kotimaisten kielten tutkimuskeskus (Institute for the Languages of Finland), 2004–, retrieved 1 January 2024

• ois, soi

Internationalism. Learned borrowing from Ancient Greek ἴσος (ísos, “equal”).

iso-

1. iso-

• is- (before a vowel)

Internationalism. Learned borrowing from Ancient Greek ἴσος (ísos, “equal”).

• IPA^(key): [ɪso]
• Hyphenation: iso

iso-

1. iso-

   Synonym: alo-

• “iso-”, in Kamus Besar Bahasa Indonesia [Great Dictionary of the Indonesian Language] (in Indonesian), Jakarta: Agency for Language Development and Cultivation – Ministry of Education, Culture, Research, and Technology of the Republic of Indonesia, 2016

• is- (before a vowel)

Internationalism. Learned borrowing from Ancient Greek ἴσος (ísos, “equal”).

iso-

1. iso-

• -osi, osi

• is- (before a vowel)

Internationalism. Learned borrowing from Ancient Greek ἴσος (ísos, “equal”).

• Hyphenation: i‧so-

iso-

1. iso-

   equi-

• “iso-”, in Dicionário Aulete Digital (in Portuguese), Rio de Janeiro: Lexikon Editora Digital, 2008–2026
• “iso-”, in Dicionário infopédia da Lingua Portuguesa (in Portuguese), Porto: Porto Editora, 2003–2026
• “iso-”, in Dicionário Priberam da Língua Portuguesa (in Portuguese), Lisbon: Priberam, 2008–2026

• is- (before a vowel)

Internationalism. Learned borrowing from Ancient Greek ἴσος (ísos, “equal”).

iso-

1. iso-

   Synonym: equi-

• “iso-”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025