undertakeragente funerário = funeral director; mortician
unflinchingcorajoso, impávido = staying strong and determined even when things are difficult; not shrinking from danger, difficulty, etc
unleash (to)desencadear, soltar
unravel (to)
desembaraçar, desemaranhar, desenredar
insustentável = not able to be defended; not able to be occupied
unwind (to)
1) desenrolar-se / 2) relaxar = to relax
upstartnouveau-riche (pejorativo)
utensilutensílio = an implement, instrument, or vessel used in a household and especially a kitchen; a useful tool or implement