Word Unit: ubi- (Latin: where)
Word Unit: udo- (Latin: rain)
Word Unit: ul- (Latin: ulos, "tail")
Word Unit: -ular (Latin: of, relating to, or resembling; compound of the suffixes -ule, "little, small" and -ar, "pertaining to, of the nature of, like"; and so, -ular is a combining form meaning: referring to something "specified": appendicular, molecular, pedicular; as well as, a combining form meaning "resembling" something specified: circular, globular, tubular)
Word Unit: ulc-, ulcer- + (Latin: sore, sore spot, painful spot)
Word Unit: -ule, -ole, -le (Latin: suffix; little, small)
Word Unit: ulno-, uln- + (Latin: elbow; larger bone of the forearm [from Greek: olene])

A related "elbow" family of words: ancon-.

Word Unit: ulo- + (Greek: wooly; curly)
Word Unit: ulo, ul (Greek: gum)
Word Unit: -ulous, -ulously (Latin: a suffix; tending to do, inclined to; full of)
Word Unit: ultim- + (Latin: end, last, final)
Word Unit: ultra-, ult- (Latin: beyond, on the other side; excessive, to an extreme degree)
Word Unit: ulula-, ululat- (Latin: howl, wail, screech, cry out)
Word Unit: -ulus, -olus, -ulum, -ola (Latin: suffix; little, small)
Word Unit: ulutat- (Latin: howl, screech, cry out)
Word Unit: -um (Greek > Latin: a suffix that forms singular nouns)
Word Unit: umbili-, umbil- (Latin: pertaining to the navel, umbilical cord; a protuberance or swelling; related to umbo, the boss [a convex elevation or knob] of a shield)
Word Unit: umbra-, umbro-, umbr-, umbel- (Latin: shade, shadow)

Other related "dark; shadow, shade; black" units: lygo-; melan-; nigri-; nocti-; nycti-; scoto-; skio-.

Word Unit: unci-, unc-, uncin- + (Greek > Latin: hook, hooked, bent, curved)
Word Unit: uncia- (Latin: inch; ounce; a twelfth)