资料来源 : pyDict

第五,第五地

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Fifthly \Fifth"ly\, adv.
   In the fifth place; as the fifth in order.

资料来源 : WordNet®

fifthly
     adv : in the fifth place; "fifthly, we must adhere to the rules
           set by the local government"