broad

Compared meaning: large in size, area, or extent (adjective).

比较义项：面积、范围或体积很大（形容词）。

• broad 本词

  Describes the width or extent across something, such as shoulders, roads or rivers; it points to the crosswise dimension of an object or area, not overall size.

  broad 强调物体或区域的宽度、跨度（如肩膀、道路、河流），指的是横向尺寸，而不是整体大小。

  He has broad shoulders that make his jackets fit tightly across the chest.

  他的肩膀很宽，穿夹克时胸部总是绷得很紧。

• extended

  Means enlarged beyond the usual or original scope, often describing an area, network or range that has been deliberately expanded; more formal than big.

  extended 表示超出原有或通常的范围而被扩大，常用来描述被刻意扩展的区域、网络或范围，语气比 big 更正式。

  The zoo built an extended habitat so the elephants have far more space to roam.

  动物园建造了一个扩大后的栖息地，让大象有更多空间可以活动。

• great

  Emphasizes size in an impressive, rather formal way, often for expanses, distances or grand things; rarely used for small everyday objects, where it can sound odd.

  great 以较为正式、令人印象深刻的方式强调“大”，常用于辽阔的地域、距离或宏伟的事物；很少用于日常小物件，用在那里会显得奇怪。

  The explorers crossed a great expanse of desert that stretched beyond the horizon.

  探险者们穿越了一片辽阔的沙漠，一直延伸到地平线之外。

• big

  The plain, everyday word for large size, used freely with almost any noun; neutral in tone and the most common choice in casual speech.

  big 是表示“大”最普通、最口语化的词，几乎可以修饰任何名词，语气中性，是日常交流中最常用的选择。

  That is a really big dog for such a small house.

  对于这么小的房子来说，那真是一只很大的狗。

Broad, extended, great and big all mean large. Broad means wide, as in broad shoulders. Extended means enlarged from before. Great is formal, for grand things. Big is the plain, common word for large. Not compared: extended's time sense, or great meaning 'excellent'.

这几个词都能表示“大”，但语气和用法不同：broad 强调“宽”这一横向维度，extended 强调范围被“扩大”，great 较为正式、带壮观意味，big 是最普通口语化的用法。这里不比较 extended 表示“（时间上）延长”的意思，也不比较 great 表示“极好的，杰出的”的意思。