Gundam Spin-offs (アナザーガンダム, Anazā Gandamu, lit. Another Gundam) is term use for Gundam works that do not use the Universal Century as the year in the works, starting with Mobile Fighter G Gundam.
(Whether it is a parallel world or not is a matter of opinion.)
The Japanese katakana of another (アナザー, anazā) tends to be a shorten term of another story (アナザーストーリー, anazā sutōrī). This term is use to mean spin-off works.