unnatural
adj.adj. different from what you expect in nature or in normal human behavior. It often describes something that feels strange, forced, or not quite right.
adj. contrary to the laws or course of nature; lacking spontaneity or appearing artificial. Often carries a negative moral or aesthetic judgment depending on the context.
The bright green color of the river looked unnatural.
He spoke in an unnatural, high-pitched voice that made everyone in the room feel slightly uncomfortable.
The rapid growth of the city created an unnatural landscape where concrete towers stood in stark, jarring contrast to the surrounding ancient forest.
From Middle English unnatural, unnaturel, equivalent to un- + natural.
Commonly used both attributively before a noun and predicatively after linking verbs like 'seem' or 'look'.