Marked by firm determination or resolution; not shakable.
marked by firm determination or resolution; not shakable; "firm convictions"; "a firm mouth"; "steadfast resolve"; "a man of unbendable perseverence"; "unwavering loyalty"
without flaws or loopholes; "an ironclad contract"; "a watertight alibi"
without flaws or loopholes; "an ironclad contract"; "a watertight alibi"; "a bulletproof argument"
without flaws or loopholes
marked by firm determination or resolution; not shakable