þyrn (noun f.) ‘thorn-bush...’

• Anon Lil 49^VII/5 — þyrni ‘[crown of] thorn’1345
• Anon Pét 6^VII/1 — þyrni ‘thorn-bush’1360
• Anon Mgr 21^VII/2 — þyrnis ‘of thorns’1394

elements in compounds