Dictionary.com
definitions

isotactic

[ahy-suh-tak-tik]
adjective Chemistry.
  1. (of a polymer) having the same configuration at successive, regularly spaced positions along the chain.See also configuration(def 4).

Origin of isotactic

First recorded in 1950–55; iso- + tactic
Related formsi·so·tac·tic·i·ty [ahy-soh-tak-tis-i-tee] /ˌaɪ soʊ tækˈtɪs ɪ ti/, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for isotactic

isotactic

adjective
  1. chem (of a stereospecific polymer) having identical steric configurations of the groups on each asymmetric carbon atom on the chainCompare syndiotactic
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012