RUBA'I

'Ruba'iyat' or 'rubaiyat' (Arabic: رباعیات) (a plural word derived from the root 'arba'a'
meaning 'four') means "quatrains" in the Persian language. Singular: 'ruba'i' ('rubai', 'ruba'ee', 'rubayi', 'rubayee'). The rhyme scheme is AABA, i.e., lines 1, 2 and 4 rhyme.
This verse form was popularized in Edward FitzGerald's translation of the collection of Persian verses known as the '''Rubaiyat of Omar Khayyam'''. In fact, ''Rubaiyat'' is a common shorthand name for this collection.
:VII
:Come, fill the Cup, and in the fire of Spring
:Your Winter-garment of Repentance fling:
:The Bird of Time has but a little way
:To flutter--and the Bird is on the Wing.
In longer poems built in rubaiyat rhyme scheme, the convention is sometimes extended so that the unrhymed line of the current stanza becomes the rhyme for the following stanza. I.e., the scheme is extended to AABA BBCB CCDC, etc.. This is sometimes called, naturally, "interlocking rubaiyat". The structure can be made cyclical by linking the unrhymed line of the final stanza back to the first stanza: ZZAZ. These more stringent systems were not, however, used by FitzGerald in his ''Rubaiyat''; it would have been particularly difficult for him to achieve this effect since the order and number of stanzas in his translation were not stable.
A prime use of the interlocking Rubaiyat in modern English poetry is "Stopping by Woods on a Snowy Evening" by Robert Frost.