um |ˈəm| — Alternative form of umbe.

umbel |ˈəmbəl| — flat-topped or rounded inflorescence characteristic of the family Umbelliferae in which the individual flower stalks arise from about the same point; youngest flowers are at the center

umbellate |ˈʌmbəlɪt| — resembling an umbel in form

umbelliferous |ˌʌmbəˈlɪfərəs| — relating to or belonging to plants of the family Umbelliferae

umber |ˈʌmbər| — an earth pigment

umbilical |ˌəmˈbɪlək(ə)l| — membranous duct connecting the fetus with the placenta

umbilicus |ʌmˈbɪlɪkəs| — a scar where the umbilical cord was attached

umbra |ˈʌmbrə| — a region of complete shadow resulting from total obstruction of light

umbrage |ˈʌmbrɪdʒ| — a feeling of anger caused by being offended

umbrageous |əmˈbreɪdʒəs| — filled with shade

umbrella |ʌmˈbrelə| — a lightweight handheld collapsible canopy

umbrella-stand |ʌmˈbreləstænd| — A container in which umbrellas are kept when drying or not in use.

umiak |ˈuːmiːæk| — (nautical) A large, open boat made of skins stretched over a wooden frame that is propelled by paddles; used by the Inuit for transportation.

umlaut |ˈʊmlaʊt| — a diacritical mark (two dots) placed over a vowel to indicate a change in sound in some languages

umpire |ˈʌmpaɪər| — an official at a baseball game

umpteen |ˌʌmpˈtiːn| — innumerable but many

umpteenth |ˈʌmpˌtɪnθ| — last in an indefinitely numerous series