Onegin stanza (sometimes "Pushkin sonnet") refers to the verse form popularized (or invented) by the Russian poet Alexander Pushkin through his novel in verse Eugene Onegin. The work was mostly written in verses of iambic tetrameter with the rhyme scheme "aBaBccDDeFFeGG", where the lowercase letters represent feminine endings (i.e., with an additional unstressed syllable) and the uppercase representing masculine ending (i.e. stressed on the final syllable).
Unlike other traditional forms, such as the Petrarchan sonnet or Shakespearean sonnet, the Onegin stanza does not divide into smaller stanzas of four lines or two in an obvious way. There are many different ways the sonnet can be divided: for example, the first four lines can form a quatrain, or instead join with the "cc" to form a set. The form's flexibility allows the author more scope to change how the semantic sections are divided from sonnet to sonnet, while keeping the sense of unity provided by following a fixed rhyme scheme. Also, being written in iambic tetrameter imparts a stronger sense of motion than other sonnets, which use the more common iambic pentameter.
John Fuller's 1980 "The Illusionists" and Jon Stallworthy's 1987 "The Nutcracker" used this stanza form, and Vikram Seth's 1986 novel The Golden Gate is written wholly in Onegin stanzas.
The Onegin stanza is also used in the verse novel Equinox by Australian writer Matthew Rubinstein, serialized daily in the Sydney Morning Herald and currently awaiting publication; in the biography in verse Richard Burgin by Diana Burgin; in the verse novel Jack the Lady Killer by HRF Keating (title borrowed from a line in Golden Gate in Onegin stanza rhymes but not always preserving the metric pattern); and in several poems by Australian poet Gwen Harwood, for instance the first part of "Class of 1927" and "Sea Eagle" (the first employs a humorous Byronic tone, but the second adapts the stanza to a spare lyrical mood, which is good evidence of the form's versatility).