A subgiant star is a star that is at an intermediate stage of its life cycle. It is bigger and brighter than a regular star like the sun, but not as massive or bright as a giant star. Full definition
6 G. Piscium is a yellow subgiant star with the stellar classification of G8 IV. (constellation-guide.com)
Schlaufman, K. C. & Winn, J. N. Evidence for the tidal destruction of hot Jupiters by subgiant stars. (nature.com)
Beta Hydri is also the closest confirmed subgiant star to Sol and one of the older as well as highly evolved stars of the Sun's spectral class in the Solar neighborhood. (members.nova.org)