expression
Used to summarize or give a concise opinion, often at the beginning of a sentence.
一言で言えば、それは無理だ。
In a word, it's impossible.
この映画を一言で言えば、感動的だった。
To put it briefly, this movie was moving.
More like 'in short' or 'the point is'; often used to rephrase or conclude, while 一言で言えば is specifically 'in one word'.
Means 'that is to say' or 'in other words'; used for paraphrasing, not necessarily brevity.
Phrase composed of 一言 (ひとこと, 'one word') + で (particle) + 言えば (conditional form of 言う, 'to say'). Literally 'if said in one word'.