Here's a breakdown of the word:
* In-: A prefix meaning "not" or "the opposite of."
* Explain: To make something clear or understandable.
* -able: A suffix meaning "capable of being."
* -ly: An adverbial suffix.
Examples:
* "The machine stopped working inexplicably."
* "The sudden change in weather was inexplicable."
* "She felt inexplicably drawn to him."
Synonyms:
* Unexplainably
* Unaccountably
* Mysteriously
* Enigmatically
* Puzzlingly
Antonyms:
* Explainably
* Understandably
* Accountably
* Clearly
* Logically