Upper-Intermediate (B2)
IPA: /ˌɪndɪˈfaɪnəbli/
KK: /ɪndɪˈfaɪnəblɪ/
Definition
In a way that cannot be clearly defined or described.
Example
The beauty of the landscape was indefinably captivating.
Conversation

I felt indefinably happy when I finished my painting yesterday.

That's awesome! It must have been a great moment for you.

Yeah, it was like a weight lifted off my shoulders.

I totally get that feeling; sometimes happiness is just indefinably overwhelming.
Synonyms & Antonyms
Synonyms
vaguely
obscurely
ambiguously
Antonyms
clearly
definitely
precisely
Root Explanation
Indefinably is formed from "in-" (meaning not), "definire" (meaning to define), and "-ably" (meaning in a manner). The word describes something that cannot be defined or described clearly.
Memory Tip
Think of 'not' ('in-') being able to 'define' ('definire') something, which is why indefinably means it cannot be clearly defined.
Visually Confused Words
undefinably
definably
undefinable
ineffably
definable