闲翻《译心雕虫》，作者讨论broad smile的翻译问题，作者认为似可直译为“宽笑”。

broad smile是一种什么样的笑? 最保险的办法就是到网上查证。

The Six Most Common Types Of Smiles And Their Hidden ...

bodylanguageproject.com/tiny-book-of-body-language/...

Broad smile. In this smile the upper and lower teeth are made visible. The gaze is relaxed and the smile is intended to convey joy and pleasure. This is a true smile and not one that is easily faked.

Anatomy of a Smile - Smile Esthetics 101

https://www.yourdentistryguide.com/smile-anatomy

When your lips form a broad smile, an imaginary line can be drawn through the corners of the mouth, from one side to the other.

broad smile实质上相当于：grin（露齿而笑; 咧着嘴笑; 龇着牙笑）

1. Grin - definition of grin by The Free Dictionary

   https://www.thefreedictionary.com/grin

   grin. 1. to smile broadly, esp. as an indication of pleasure, amusement, or the like. 2. to draw back the lips so as to show the teeth, as a snarling dog or a person in pain. 3. to express by grinning. n. 4. a broad smile. 5. the act of producing a broad smile.