vestigially

adjective

1. of, relating to, or of the nature of a vestige: a vestigial tail.

adjective

1. of, relating to, or being a vestige
2. (of certain organs or parts of organisms) having attained a simple structure and reduced size and function during the evolution of the speciesthe vestigial pelvic girdle of a snake

adj.

1877, from vestige + -al (1).

adj.

1. Occurring or persisting as a rudimentary or degenerate structure.

1. Relating to a body part that has become small and lost its use because of evolutionary change. Whales, for example, have small bones located in the muscles of their body walls that are vestigial bones of hips and hind limbs.