synergistic effect of toxic substances(1. A state in which the combined effect of two or more substances is greater than the sum of the separate effects. 2. An effect whereby two toxic substance together have more of an impact than anticipated)
synthetic detergent(An artificially produced solid or liquid cleansing substance that acts like soap but is stronger, and is capable of dissolving oily materials and dispersing them in water)
synthetic textile fibre(An artificially produced filament or threadlike strand used by manufacturers to produce clothes or other goods that require weaving, knitting or felting, including polyester, nylon, rayon and other similar material)