atactic

[ ey-tak-tik ]
/ eɪˈtæk tɪk /

adjective Chemistry.

(of a polymer) not stereospecific; lacking tacticity.

Origin of atactic

1955–60; a-6 + -tactic, back formation from tacticity
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for atactic

atactic
/ (eɪˈtæktɪk) /

adjective

chem (of a polymer) having random sequence of the stereochemical arrangement of groups on carbon atoms in the chain; not stereospecific
pathol relating to or displaying ataxia
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