head to head

形容词 head to head:

1. involving two persons; intimately private
   同义词：tete-a-tete, head-to-head
2. inconclusive as to outcome; close or just even in a race or comparison or competition
   同义词：neck and neck, head-to-head, nip and tuck

副词 head to head:

1. even or close in a race or competition or comparison
   同义词：neck and neck, head-to-head, nip and tuck