sandthorn UK /ˈsænd.θɔːn/US /ˈsænd.θɔɹn/ noun1 •A species of sea buckthorn (Hippophae rhamnoides), found from western Europe to northwestern China.They likewise must ascend mountains by degrees and not make extraordinary leap of the Sandthorn, Hippophae rhamnoides... — 1837 formssandthorns