restharrow
Concise Oxford English Dictionary © 2008 Oxford University Press:
restharrow/ˈrɛstharəʊ/
▶noun a sticky leguminous plant which has pink flowers and creeping woody stems with spines. [Genus Ononis.]
– origin C16: from obs. rest ‘stop, arrest’ + harrow (because the tough stems impeded the progress of a harrow).
'restharrow' also found in these Oxford entries:

