A "subgiant" is a star that is in a transitional stage between being a regular main sequence star (like our Sun) and an evolved giant star. It is larger and hotter than a main sequence star, but smaller and cooler than a giant star. Full definition
Future monitoring of the transits of this system may enable the detection of period decay and constrain the tidal dissipation rates of subgiant stars. (arxiv.org)
Star A is probably a yellow - orange subgiant of spectral and luminosity type G0 IV (NASA Stars and Exoplanet Database; and Garrison and Beattie, 1998). (members.nova.org)
Our stellar sample ranges from M dwarfs with masses as low as 0.2 Msun to intermediate - mass subgiants with masses as high as 1.9 Msun. (arxiv.org)