tir(a)-, n. Wood. Gender: B, Stems: /rː/ <rr> - /r/ <r> - /r/ <r>, Ablaut: /i/ <i> - /i/ <i> - /i/ <i>, Nominative singular: /tirːa/ <tirra>, Accusative singular: /tiri/ <tiri>, Allative singular: /tiraβɒ/ <tirabå> This is commonly used in compounds to form the names of types of wood.