A unicase or unicameral alphabet is one that has no case for its letters. Telugu, Kannada, Tamil, Arabic, Old Hungarian, Hebrew, Iberian, Georgian, and Hangul are unicase alphabets, while (modern) Latin, Greek, Cyrillic, and Armenian are bicameral, as they have two cases for each letter, e.g., B/b, Β/β, Б/б, Բ/բ. Individual characters can also be called unicameral if they are used as letters with a generally bicameral alphabet but have only one form for both cases; for example, ʻokina (ʻ), used in Polynesian languages, and glottal stop (ʔ) as used in Nuu-chah-nuulth.
All alphabets with case were once unicase. Latin, for example, used to be written with a unicase alphabet in imperial Roman times; it was only later that scribes developed new sets of symbols for running text, which became the lower case of the Latin alphabet, while the letterforms of Ancient Rome came to be called capitals or upper case.
The Georgian alphabet, on the other hand, has developed in the other direction: in the medieval period, Georgian also had two sets of letters available for bicameral writing, but the use of two cases later gave way to a unicameral system. The ecclesiastical form of the Georgian alphabet, Khutsuri, had an upper case called Asomtavruli (like the Ancient Roman capitals) and a lower case called Nuskhuri (like the medieval Latin scribal forms). Out of Nuskhuri came a secular alphabet called Mkhedruli, which is the unicase Georgian alphabet in use today.
A unicase version of the Latin alphabet was proposed by Michael Mann and David Dalby in 1982 as a variation of the Niamey African Reference Alphabet. This version has apparently never been actively used. Another example of unicase Latin alphabet is the Initial Teaching Alphabet. Occasionally some fonts use unicase designs to create an unusual effect; this was particularly popular in the 1960s.
The International Phonetic Alphabet only uses lowercase Latin (and Greek) letters and some scaled upper-case letters (small caps), effectively making it a unicase alphabet, although it is not used for ordinary writing of any language.