|a scrap or morsel of food left at a meal.|
|a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.|
A diagram used to help describe and visualize the possible interactions between particles in quantum electrodynamics and quantum chromodynamics. Fermions, such as electrons, are represented with straight lines and bosons, such as photons, with wavy lines. Points of intersection indicate an interaction, such as an electromagnetic interaction, between the particles.