D defs.my
Entry 1 sense Webster, 1913

one-upmanship

· IPA /wənˈəpmənˌʃɪp/
01 n. The attitude or practice of trying to keep one step ahead of a friend or competitor; vigorous competitiveness.
  1. 1.
    The attitude or practice of trying to keep one step ahead of a friend or competitor; vigorous competitiveness.