Definition

Someone who is tireless and never seems to get tired, continuing to work or do things without stopping.

Example

Her indefatigable spirit inspired everyone around her to keep going, no matter the challenges they faced.

Conversation

I really admire how you can keep going all day without getting tired.

Thanks! I guess I’m just naturally indefatigable when it comes to my hobbies.

It’s impressive, though — I wish I had that kind of energy.

You can definitely build up your stamina; just start small and stay consistent!

Synonyms & Antonyms

Root Explanation

Indefatigable is formed from "in-" (meaning not) and "defatigabilis" (from Latin "defatigare", meaning to tire out). The word describes someone who is not able to be tired out, hence, tireless or unflagging.

Memory Tip

Think of someone who is 'not' ('in-') able to be 'tired out' ('defatigare') — that's why indefatigable means tireless.

Visually Confused Words