Synonyms for Second-rate:

adj.

imperfect (adjective)
deficient, blemished, incomplete, defective, imperfect, flawed, blotched, faulty, tainted, spoiled, inadequate.
inferior (adjective)
substandard, low-grade.
lousy (adjective)
faulty.
mean (adjective)
pitiful.
mediocre (adjective)
common.
second-class (adjective)
second class.
second-rate/second-class (adjective)
mean.

n.

disgraceful, dire, pitiful, embarrassing. substandard, low-grade, better, low quality, second class, shabby, common, mean. inferior (noun)
substandard, low-grade.

Other synonyms:

pitiful, second class, dire, embarrassing, low quality. shabby. commonplace
common.
Other relevant words:
low quality, common, poor, embarrassing, mediocre, mean, dire, low-grade, substandard, shabby, pitiful.