the word 'testamentary' is a legal english adjective formed from the noun 'testament' and the suffix '-ary'. its core, 'testament', originates from latin 'testamentum', meaning a formal will or covenant, which itself derives from 'testari' (to bear witness), rooted in 'testis' (witness). this reflects the ancient legal concept of a will as a witnessed document. the suffix '-ary', from latin '-arius', denotes a relationship or pertinence. thus, the literal construction "pertaining to a will" directly and logically yields the modern legal meaning concerning anything related to or established by a last will and testament.

Structure: testament (will) + ary (relating to) - testament: from latin 'testamentum' (a will, covenant), from 'testari' (to bear witness), from 'testis' (witness). functions as the core noun root. - ary: from latin '-arius' (pertaining to, connected with). functions as an adjective-forming suffix.