upper hand

WordReference Random House Learner's Dictionary of American English © 2025

ˈup•per ˈhand, n. [countable* usually singular;
usually: the + ~]

1. a controlling position;
   advantage:
   tried to gain the upper hand in the negotiations.

WordReference Random House Unabridged Dictionary of American English © 2025

up′per hand′, 

1. the dominating or controlling position;
   advantage:
   to have the upper hand in the fight.

• 1475–85

Collins Concise English Dictionary © HarperCollins Publishers::

upper hand noun

1. the upper hand ⇒ the position of control; advantage (esp in the phrases haveorget the upper hand)