Decide v. t. : To cut off; to separate.

Decide v. t. : To bring to a termination, as a question, controversy, struggle, by giving the victory to one side or party; to render judgment concerning; to determine; to settle.

Decide v. i. : To determine; to form a definite opinion; to come to a conclusion; to give decision; as, the court decided in favor of the defendant.

Example:
How do you Decide between two relationships that are complete opposites?

Taxonomy
idioms, intr, décider, settle, Synonyms, cid, dispute, judgment, Devil's Dictionary, Houghton Mifflin Company, Literature & Language, Dictionary, cides, conclusively, contention, uncertainty, rule, Thesaurus.

Defination from the web:
decide ( ) v. , -cided , -ciding , -cides . v.tr. To settle conclusively all contention or uncertainty about: decide a case; decided the dispute in ... SYNONYMS decide, determine, settle, rule, conclude, resolve. These verbs mean to come to a decision. ...