1840, "friendship," from crony + -ism. Meaning "appointment of friends to important positions, regardless of ability" is originally American English, by 1952.
Entries linking to cronyism
crony n.
"old familiar friend, intimate companion," 1660s, chrony, Cambridge student slang, probably from Greek khronios "long-lasting," from khronos "time" (see chrono-), on the notion of "old friend" or "a contemporary."
-ism
word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.