The Pechenegs were mentioned as Bjnak, Bjanak or Bajanak in medieval Arabic and Persian texts, as Be-ča-nag in Classical Tibetan documents, as Pačanak-i in works written in Georgian. Anna Komnene and other Byzantine authors referred to them as Patzinakoi or Patzinakitai. In medieval Latin texts, the Pechenegs were referred to as Pizenaci, Bisseni or Bessi. East Slavic peoples use the terms Pečenegi or Pečenezi, while the Poles mention them as Pieczyngowie or Piecinigi. The Hungarian word for Pecheneg is besenyő; the Romanian term is "Pecenegi" The ethnonym may have derived from the Old Turkic word for "brother-in-law” (baja, baja-naq or bajinaq), implying that it initially referred to an "in-law related clan or tribe".. Pechenegs are mentioned as one of 24 ancient tribes of Oghuzes by 14th century statesman and historian of Ilkhanate-ruled Iran Rashid-al-Din Hamadani in his work Jāmiʿ al-Tawārīkh ("Compendium of Chronicles") with the meaning of the ethnonym as "the one who shows eagerness". 17th century Khan of Khanate of Khiva and historian Abu al-Ghazi Bahadur mentions the pechenegs as bechene among 24 ancient tribes of Turkmens (or Oghuzes) in his book
Shajare-i Tarakime (“Genealogy of the Turkmen") and provides for its meaning as "the one who makes".
Three of the eight Pecheneg "provinces" or clans were collectively known as Kangars. According to Constantine VII Porphyrogenitus, the Kangars received this denomination because "they are more valiant and noble than the rest" of the people "and that is what the title Kangar signifies". For no Turkic word with similar meaning is known, Ármin Vámbéry connected the ethnonym to the Kirghiz words kangir ("agile"), kangirmak ("to go out riding") and kani-kara ("black-blooded"), while Carlile Aylmer Macartney associated it with the Chagatai word gang ("chariot"). Omeljan Pritsak proposed that the name had initially been a composite term (Kängär As) deriving from the Tocharian word for stone (kank) and the Iranian ethnonym As. If the latter assumption is valid, the Kangars' ethnonym suggests that Iranian elements contributed to the formation of the Pecheneg people.