Open English Wordnet
Adjectives
(s)tete-a-tete, head-to-headinvolving two persons; intimately private“a tete-a-tete supper”, “a head-to-head conversation”
(s)neck and neck, head-to-head, nip and tuckinconclusive as to outcome; close or just even in a race or comparison or competition“as they approached the finish line they were neck and neck”, “the election was a nip and tuck affair”
Adverbs
(r)neck and neck, head-to-head, nip and tuckeven or close in a race or competition or comparison“the horses ran neck and neck”, “he won nip and tuck”