trepan

trepan
/trɪˈpæn; trɪ`pæn/ v
(-nn-) [Tn]
(medical 医) = trephine. trepan, n
1 (medical 医) early form of trephine （早期的）环钻, 环锯.
2 (engineering 工) bore for drilling a mine shaft 钻井机.

牛津英汉双解词典