occidendus

Future passive participle (gerundive) of occīdō (“fell; slay”).

occīdendus (feminine occīdenda, neuter occīdendum); first/second-declension participle

1. which is to be felled, which is to be cut to the ground; which is to be beaten, which is to be smashed, which is to be crushed
2. which is to be killed, which is to be slain, which is to be slaughtered
3. (by extension) which is to be plagued to death, which is to be tortured, which is to be tormented, which is to be pestered

First/second-declension adjective.