Full and faithful

A functor F: C -> D is full and faithful just when, for all categories X and functors G, H: X -> C, the whiskering action of F induces a bijection between [G, H] and [FG, FH] (where [G, H] denotes the set of natural transformations from G to H). Clearly this formulation makes sense in any bicategory. Is there a name for 1-cells with this property? Thanks! Robin