The word "order" means the arrangement or organization of something in a particular sequence. Synonyms for "order" include instructions, directives, commands, rules, regulations, or guidelines.
The word "testify" means to give evidence or witness to something. Synonyms for "testify" include declare, attest, affirm, protest, swear, state, and vow.
Combining both words, "order testify" could be interpreted as giving evidence or witness according to a particular arrangement or organization. Synonyms for this phrase include testify under oath, provide a testimony, bear witness, give a statement, and declare under penalty of perjury. The meaning of the phrase depends on the context in which it is used.