umbilicus

n (anatomy 解) navel 脐.

ulceration, ulcerous, ulna, ulterior, ultimate, ultimately, ultimatum, ultimo, ultra violet, ultra-, ultramarine, ultrasonic, ultrasound, ultraviolet, ululate, ululation, Ulyanovsk, umber, umbilical, umbilical cord, umbra, umbrage, umbrella, umlaut, umpire, umpteen, umpteenth, un, un-, un-American, unabashed, unabated, unable, unabridged, unacceptable, unacceptably, unaccommodating, unaccompanied, unaccountable, unaccountably,