unwavering

adjectives

marked by firm determination or resolution; not shakable
"firm convictions"; "a firm mouth"; "steadfast resolve"; "a man of unbendable perseverence"; "unwavering loyalty"
firm, steadfast, steady, stiff, unbendable, unfaltering, unshakable, unwavering
not showing abrupt variations
"spoke in a level voice"; "she gave him a level look"- Louis Auchincloss
level, unwavering