| silver wattle | (n) evergreen Australasian tree having white or silvery bark and young leaves and yellow flowers, Syn. Acacia dealbata, mimosa |
| silver wedding anniversary | (n) the 25th wedding anniversary |
| silver whiting | (n) a dull silvery whiting of southern Atlantic and Gulf Coasts of the United States, Syn. Menticirrhus littoralis |
| silver willow | (n) North American willow with greyish silky pubescent leaves that usually blacken in drying, Syn. silky willow, Salix sericea, Salix alba sericea |