biodegradable /(ˌ)baɪoʊdəˈɡɹeɪdəbl̩/adjective 1noun 1forms 3 adjective1 •Capable of being decomposed by biological activity, especially by microorganisms.Similar studies of rats have employed four different intracranial resorbable, slow sustained release systems—surgical foam, a thermal gel depot, a microcapsule or biodegradable polymer beads. — 2013 noun1 •Any material that can be decomposed by biological activity. formsbiodegradables · more biodegradable · most biodegradable