Mid 17th century (originally Cambridge university slang): from Greek khronios 'long-lasting' (here used to mean 'contemporary'), from khronos 'time'. Compare with chum¹.

• This derives from Greek khronios ‘long-lasting’, which was based on khronos ‘time’. In the 17th century crony was Cambridge University slang for ‘an old friend’ or ‘a contemporary’. Chum is the Oxford University equivalent. The first record of crony is from the diary of Samuel Pepys (1633–1703), a former Cambridge man, for 30 May 1665: ‘Jack Cole, my old school-fellow…who was a great chrony of mine.’ His spelling showed the word's direct relationship with the original Greek. The political sense of cronyism, ‘the appointment of your friends and associates to positions of authority’, originated in the US during the 19th century. See also chronic