initiator
(ɪˈnɪʃɪeɪtə(r))
[a. late L. initiātor (Tertull.), agent-n. f. initiāre to initiate.]
a. One who or that which initiates.
| 1676 Coles, Initiator, which doth initiate. 1738 Warburton Div. Legat. ii. iv. Wks. 1811 II. 68 The interpreters of these holy Mysteries, the Hierophants and Initiators. 1822 T. Taylor Apuleius 276 Initiators into the mysteries. 1847 Lewes Hist. Philos. (1853) 125 Regarded as the initiator of a new epoch. 1943 [see articulator 4]. 1971 I. F. Hancock in J. Spencer Eng. Lang. W. Afr. 117 The process of creolising in the direction of a language other than the initiator language of the pidgin form has been rather misleadingly called relexification. |
b. An explosive or device used to detonate the main charge.
| 1915 A. Marshall Explosives xxix. 417 Of all these explosives silver azide, mercury fulminate, and the aldehyde are the only ones that have a sufficiently high acceleration to be of any use as initiators of detonation. 1944 Compt. Rend. (Doklady) de l'Acad. des Sci. de l'URSS XLIV. 18 One might naturally expect that the flash-point..would be lower for the initiators than for secondary explosives. 1962 Ordnance Technical Terminol. (U.S. Army Ordnance School) (AD 660112) 164/1 Initiator, a device used as the first element of an explosive train, such as a detonator or squib... It generally contains a small quantity of a sensitive explosive. 1964 M. Gowing Britain & Atomic Energy ix. 264 His criticism enlivened discussions on bomb assembly, and he participated very actively in the design of the initiator. |
c. Chem. Any substance which starts a polymerization reaction.
| 1940 in Chambers's Techn. Dict. 1951 Frith & Tuckett Linear Polymers ii. 50 In any large-scale production of a polymer, catalytic initiation is nearly always used... The word ‘catalyst’ in this connection is rather a misnomer, as it is almost always destroyed in starting off polymerisation; ‘initiator’ is less open to objection, but has never really established itself. 1959 Cram & Hammond Org. Chem. xxv. 573 There are three principal classes of free-radical initiators: 1. Compounds..which undergo thermal decomposition... 2. Photosensitizers... 3. Redox systems. 1972 Billingham & Jenkins in A. D. Jenkins Polymer Sci. i. i. 19 Azo-bis-isobutyronitrile is very frequently used as an initiator for research studies on radical polymerization. |