This is the 7329th most frequent Japanese word.
云っ
The word "云っ" is a conjugation of "云う" (an old or formal variant of "言う"), meaning "to say" or "to speak" in English.
The word '云った' here is used as the past tense of '言う' (to say) to indicate that the subject talked or stated something.
彼女は理由を云った。
She explained the reason.
In this sentence, '云った' is attributing a quotation or spoken words to the subject, indicating that he verbally expressed the statement.
「だから違うんだ」と彼は云った。
"That's why it's different," he said.
The term '云って' here serves as the gerund form for '言う,' facilitating the action of asking someone to say or explain in detail.