言葉を尽くす
ことばをつくす
to exhaust one's vocabulary (in trying to persuade someone or explain something, etc.)
言葉を濁す is read as ことばをにごす (kotoba o nigosu) and means to be vague.
ことばをにごす
kotoba o nigosu
ことばをつくす
to exhaust one's vocabulary (in trying to persuade someone or explain something, etc.)