Correct spelling for the English word "uncipressure" is [ʌnsˈɪpɹɛʃə], [ʌnsˈɪpɹɛʃə], [ʌ_n_s_ˈɪ_p_ɹ_ɛ_ʃ_ə] (IPA phonetic alphabet).
Arrest of hemorrhage from a cut artery by pressure with a blunt hook.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.