IPA: /ˌæn.ɪ.səˈtrɒ.pɪ.kli/
KK: /ˌænɪsəˈtrɒpɪkli/
In a way that varies depending on the direction; not uniform in all directions.
The material behaves anisotropically, showing different properties when measured from different angles.
Anisotropically → It is formed from "an-" (meaning not), "isotropus" (from Greek "isos" meaning equal and "tropos" meaning direction), and "-ically" (meaning in a manner). The word describes something that does not have identical properties in all directions.
Think of 'not' ('an-') having 'equal direction' ('isotropus') — that's why anisotropically means something that behaves differently in different directions.