know (someone) by sight
знать кого-либо в лицо (знать только имя и узнавать по внешности)
I can't say that I know Lily well, actually I know her by sight only.
Другие идиомы:
- know one's ABCs
- know the ropes
- know (someone or something) like the back of one's hand
- know when one is not wanted
- know all the tricks of the trade
- know better (than to do something)
- know a thing or two (about someone or something)
- know a trick or two
- know-how
- not know if one is coming or going
- know (something) in one's bones
- know (something) backwards and forwards
- know where all the bodies are buried
- know which side one's bread is buttered on
- not know the first thing about something