1) Chemical action 2) Chemical change 3) Chemical process 
In chemistry, acylation (rarely, but more formally: alkanoylation) is the process of adding an acyl group to a compound. The compound providing the acyl group is called the acylating agent. Because they form a strong electrophile when treated with some metal catalysts, acyl halides are commonly used as acylating agents. For example, Friedel-Crafts...
The introduction of an acid radical into the molecule of a chemical compound. ... (12 Dec 1998) ... 
(a″sә-la´shәn) introduction of an acyl radical into the molecule of a compound.
Introduction of an acyl (RCO-) group into a molecule: for example the formation of an ester between glycerol and fatty acid to form mono-, di-, or tri-acylglycerol, or the formation of an aminoacyl-tRNA during protein synthesis. Acyl-enzyme intermediates are transiently formed during covalent catalysis.
Type: Term Pronunciation: as′i-lā′shŭn Definitions: 1. Introduction of an acyl radical into an organic compound or formation of such a radical within an organic compound.
[n] - the process of introducing an acyl group into a compound
noun the process of introducing an acyl group into a compound