Collaterally \Col*lat"er*al*ly\, adv. 1. Side by side; by the side. [1913 Webster] These pulleys . . . placed collaterally. --Bp. Wilkins. [1913 Webster] 2. In an indirect or subordinate manner; indirectly. [1913 Webster] The will hath force upon the conscience collaterally and indirectly. --Jer. Taylor. [1913 Webster] 3. In collateral relation; not lineally. [1913 Webster]