A phrase meaning “to say it in a word” or “in short,” used to state the main point or conclusion concisely.
一言で言えば、プロジェクトは成功した。
In short, the project succeeded.
彼の説明は複雑だったが、一言で言えば顧客のニーズを満たしていないということだ。
His explanation was complicated, but in a word it means he isn't meeting the customer's needs.
一言で言えば、この問題は時間と資金の不足が原因だ。
To put it briefly, this problem is caused by a lack of time and funds.