look daggers at (one)
To glare at someone very angrily, spitefully, or disdainfully. I noticed the bride looking daggers at the best man as he started making vulgar jokes during his speech.
look daggers
Glare, stare fiercely, as in When she started to discuss their finances, he looked daggers at her. This metaphoric term, likening an angry expression to a dagger's thrust, dates from ancient times and has appeared in English since about 1600.