undesigning, a. [artless], [guileless], [sincere].
undesirable, a. inexpedient; [objectionable], [unacceptable], [ineligible].
undetermined, a. [unsettled], [irresolute], [wavering], indeterminate, abeyant.
undeveloped, a. in [embryo], embryonic, [immature], abeyant, [embryo], [imperfect]; atrophied, dwarfed, [rudimentary], [stunted], [abortive], [puny].
undevelopment, n. immaturity; atrophy, [abortion]; [embryo].
undignified, a. [unseemly], [unbecoming], [groveling], [servile], [obsequious].
undiminished, a. [unabated], unlessened.
undiscernible, a. imperceptible, indiscernible.
undisputable, a. incontrovertible, incontestable, [indisputable], [undeniable].
undissolvable, a. [insoluble], [indissolvable], indissoluble.