Synonyms for Mediocre:

adj.

all (adjective)
second-rate.
average (adjective)
dominant, mid, medium, conventional, run-of-the-mill, average, middle-of-the-road, mean, common, predominant, middling, everyday, moderate, standard, commonplace, normal, dull, customary, ordinary, median, stock, usual, stereotype, midmost, halfway, mezzo.
average, commonplace (adjective)
fair, unexceptional, inferior, mean, ordinary, run-of-the-mill, middling, indifferent, moderate, dull, undistinguished, conventional, medium, so-so, intermediate, standard, common, second-rate.
inferior (adjective)
low-grade.
mediocre (adjective)
mundane, modest, suburban, common, banal, normal, so-so, routine, standard, usual, average, ordinary, mean.
middle (adjective)
equidistant, core, medium, mid, half-and-half, geocentric, halfway, pivotal, midmost, average, nuclear, Bisecting, median, central, half, intermediate, mezzo, mean, middle, middle-of-the-road, middling, axial, centralized, medial.
second-class (adjective)
second class.
unexceptional (adjective)
unexceptional.

n.

garden-variety, indifferent, undistinguished, cut-and-dried, plain, formulaic, unremarkable, good, unexceptional, garden. better, low-grade, substandard, low quality, second class, shabby. mediocre (noun)
bad, average, inferior, second-rate, middling, fair, poor, ordinary.

Other synonyms:

unexceptional, unremarkable, garden-variety, formulaic, cut-and-dried, low quality, second class. low-grade, substandard, undistinguished, garden. shabby. plain. ordinary
indifferent.
unsatisfactory
disappointing.

Usage examples for mediocre

  1. Transferred to another organization, he may prove mediocre or even undesirable, in his services. – Analyzing Character by Katherine M. H. Blackford and Arthur Newcomb
  2. I felt in my heart that the further one ventures the better one understands how everything in our life is common, short, and empty; that it is in seeking the unknown in our sensations that we discover how mediocre are our attempts and how soon defeated! – 'Twixt Land & Sea by Joseph Conrad