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1. An act of colliding; a crash.
2. A condition of opposition or conflict between two or more people or things: the collision between management and labor.
3. Physics A brief dynamic event consisting of the close approach of two or more particles, such as atoms, resulting in an abrupt change of momentum or exchange of energy.

[Middle English, from Late Latin collīsiō, collīsiōn-, from Latin collīsus, past participle of collīdere, to collide; see collide.]

col·li′sion·al adj.
col·li′sion·al·ly adv.
Synonyms: collision, crash1, impact
These nouns denote violent forcible contact between two or more things: the midair collision of two planes; a crash involving two cars; a crater produced by the comet's impact.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


in the manner of a collision or collisions
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
Cartridge-based helium damping gas for collisionally induced dissociation during tandem MS experiments is incorporated in the overall instrument design and delivered at 40 psi, whereas [N.sub.2] nebulizing gas was provided by a standalone gas canister or a small SCBA tank for field usage at a constant pressure of 100 psi.
Frantzeskakis, "Matter-wave solitons of collisionally inhomogeneous condensates," Physical Review A, vol.
Source conditions were as follows: Curtain Gas, 40; gas 1, 35; gas 2, 30; temperature, 600; collisionally activated dissociation gas, 12; ion spray voltage, 5500; and entrance potential, 10.
Post-translational modifications of integral membrane proteins resolved by top-down Fourier transform mass spectrometry with collisionally activated dissociation.