1. (

• firm ,
• steadfast ,
• steady ,
• stiff ,
• unbendable ,
• unfaltering ,
• unshakable ,
• unwavering

) marked by firm determination or resolution; not shakable; "firm convictions"; "a firm mouth"; "steadfast resolve"; "a man of unbendable perseverence"; "unwavering loyalty" ;

2. (

• level ,
• unwavering

) not showing abrupt variations; "spoke in a level voice"; "she gave him a level look"- Louis Auchincloss ;