Synonyms for Undue:

adj.

excessive, unnecessary (adjective)
inordinate, sinister, indecorous, unfair, forbidden, exorbitant, disproportionate, too great, extreme, unwarranted, unjust, overmuch, unjustified, illegal, immoderate, unreasonable, underhanded.
improper (adjective)
un, underhanded, indecorous, unnecessary, unjust, unfair, forbidden, disproportionate, too great, extreme, sinister, illegal, MLY.
unjust (adjective)
unfair.
unwarranted (adjective)
unwarranted.

n.

over, too, surplus, exceptional, more, beyond, overly, Hyper-. extreme, exorbitant, excess, overmuch, overabundant. undue (noun)
inordinate, excessive, unreasonable, not due, unjustified, unwarranted, immoderate.

Other synonyms:

overmuch, overabundant. exorbitant. extreme.

Usage examples for undue

  1. Sir Austin had an unpleasant office to require of his son; no other than that of humbly begging Benson's pardon, and washing out the undue blood he had spilt in taking his Pound of Flesh. – The Complete Project Gutenberg Works of George Meredith by George Meredith
  2. Don't give him no undue lee- way ter fleece ye. – A Pagan of the Hills by Charles Neville Buck
  3. Otherwise some particular episode might cause undue mental stress, and set up a block. – Monkey On His Back by Charles V. De Vet