Lewis & Short

sŭper -immĭnĕo, ēre, v. n., to hang over, overhang (very rare): pastorem Ense sequens nudo superimminet, Verg. A. 12, 306: terrā superimminente, Sen. Q. N. 5, 15, 1: virgineusque pudor zonae superimminet artus, Avien. Arat. 962: mons superimminens, Hilar, in Psa. 124, 3.