Definition

Something that cannot be challenged, doubted, or attacked; it is certain and secure.

Example

The scientist presented unassailable evidence that supported her theory.

Conversation

I think his argument was completely unassailable during the debate.

Yeah, he really had solid evidence to back it up.

It made it hard for the other side to respond effectively.

For sure, once you have unassailable points, it's tough to counter.

Synonyms & Antonyms

Root Explanation

Unassailable → It is formed from "un-" (meaning not) and "assail" (from Old French *assailir*, meaning to attack) and the suffix "-able" (meaning capable of). The word describes something that cannot be attacked or is invulnerable.

Memory Tip

Think of something that is 'not' ('un-') able to be 'attacked' ('assail') — that's why unassailable means it cannot be attacked.

Visually Confused Words