zero-derivedhttp://www.oed.com/dictionary/zero-derived_adj%3Ftab%3Dmeaning_and_usezero-derived, adj.
Revised 2018

zero-derivedadjective

Linguistics.
  1. 1971–
    (Of a word) having a form unaltered from that of the word of which it is a derivative.
    See note at zero derivation n.
    1. 1971
      The implication of Whorf's position and similar views which deny a derivational relationship between zero-derived words and their bases are discussed by D. Kastovsky.
      Found. Language vol. 7 214
    2. 2015
      It appears that zero-derived nouns account for a relatively small class of place nouns in present-day English.
      B. Szymanek in P. O. Müller et al., Word-formation: Handbook Languages Europe vol. II. vii. 1335

Originally published as part of the entry for zero, n. & adj.

zero, n. & adj. was revised in June 2018.