1. (

• indefensible ,
• untenable

) (of theories etc) incapable of being defended or justified ;

2. (

• indefensible

) not able to be protected against attack ;

3. (

• indefensible ,
• insupportable ,
• unjustifiable ,
• unwarrantable ,
• unwarranted

) incapable of being justified or explained ;