Definition of "orexigenic"

Ghrelin is a 28‐amino acid acylated peptide predominantly secreted by the stomach but also by the brain. In mammals, ghrelin stimulates both GH [growth hormone] secretion and appetite, and it is the only GI [gastrointestinal] hormone with confirmed orexigenic properties […].

2009, Hélène Volkoff, Saraj Unniappan, Scott P. Kelly, “The Endocrine Regulation of Food Intake”, in Nicholas J. Bernier, Glen Van Der Kraak, Anthony P. Farrell, Colin J. Brauner, editors, Fish Neuroendocrinology (Fish Physiology; 28), London, Amsterdam: Academic Press, section 2 (Endocrine Regulation), page 434