Hi Daley:
The verb forms would be: (a) to explain (b) to describe (c) to clarify
I think "explain" is the more common word in general conversation.
Describe could apply to anything either physical or non-physical.
Clarify is not necessarily distinct, because to explain, is to describe something, which equates to the clarification of some subject.
Many students of English have difficulties with Synonyms, which is your difficulty here.
Oddly, many students ask continually for the "differences" in meaning.
Differences pertain generally, to Antonyms, the words with Opposite Meanings.
Synonyms have "like or similar" meanings. Type any word for a search like this, and you will learn much: CLARIFY + SYNONYMS
EXPLAIN + SYNONYMS DESCRIBE + SYNONYMS.
The power of English is the great variety of terms it can use to communicate its ideas.
Otherwise, all we would do is reduced the entire language to a few primitive words and expressions.
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