From Latin controversia + -al; see controversy.

• (RP) IPA: /ˌkɒn.tɹəˈvɜː.ʃəl/, /ˌkɒn.tɹəˈvɜː.sjəl/
• (America) IPA: /ˌkɑn.tɹəˈvɝ.ʃəl/, /ˌkɑn.tɹəˈvɝ.sjəl/, /ˌkɑn.tɹəˈvɝ.si.əl/
• (Australia) IPA: /ˌkɔn.tɹəˈvɜː.ʃəl/

controversial

1. Arousing controversy—a debate or discussion of opposing opinions.
   • 1849–1861, Thomas Babington Macaulay, The History of England from the Accession of James the Second, volume (please specify |volume=I to V), London: Longman, Brown, Green, and Longmans, →OCLC ↗:

     Whole libraries of controversial books.

• contentious
• contested

• uncontroversial
• noncontroversial, non-controversial
• incontrovertible

• controversialist
• controversiality
• controversy
• controvert
• controverter
• controvertible

• French: controversé, polémique
• German: umstritten, kontrovers
• Italian: controverso
• Portuguese: polémico (Portugal), polêmico (Brazil), controverso
• Russian: спо́рный
• Spanish: polémico, controvertido, controversial (Latin America, Anglicism)

controversial (plural controversials)

1. (rare) Someone or something that is controversial.