Fan-terminology for a certain class of combiners -- generally used only for "big robot" combiners with emergent personalities. The term is nebulously defined, such that some fans would consider a two-member combiner such as 
Squawkbox a gestalt, but other fans would not. This is probably the fandom's second most frequently-used term for combining Transformers. Its use in Transfandom is derived from the principle of 
gestalt psychology, which is sometimes simplified to mean "greater/different than the sum of its parts," though a few fans consider this term pretentious and obtuse. The term remained firmly in realm of 
fanon for years, although it did appear in some 
Energon design sketches implying that Hasbro designers used the term occasionally, until in 2007 "gestalt" made its first official appearance, in the bio of the 
Titanium Series Menasor toy.