Why Krishna is called Ranchhod or Ranchhod ray. In Gujarat we also sing Jay Ranchhod Makhanchor.
"Rann" means "battlefield" & "chhod" means "abandon". The one who abandons a battlefield usually out of fear or other concerns can be termed as "Rannchhod".
Krishna lived his majority of life as Leela, where he showed various colors (Rasa-s). "Fear" was one of them. Krishna was Not a freak (ghora/extreme) of any particular good/bad virtue; he had it all balanced.
This derogatory name might have been coined because of Krishna along with other Yadu-s running away [from a possible battle] against JarAsandha (father in law of Kansa). There can be other stories too, but not find-able in current version of MahAbhArata.
In Krishna's words from Sabha Parva:
Then the widow of Kansa and the daughter of Jarasandha, that handsome woman with eyes like lotus-petals, grieved at the death of her lord, went unto her father, and repeatedly urged, O Monarch, the king of Magadha, saying,--O slayer of all foes, kill thou the slayer of my husband.--Then, O great king, remembering the conclusion to which we had come of old we became exceedingly cheerless and fled from Mathura. Dividing our large wealth into small portions so as to make each portion easily portable, we fled from fear of Jarasandha, with our cousins and relatives. Reflecting upon everything, we fled towards the west.
Later they all landed & settled in Dwaraka, Gujarat. This "insulting" name is also celebrated as part of his colourful life! Other such names, which were derogatory but now celebrated are:
- Makhhan-chor ("butter stealer")
- Gau-pal ("cowherd")
- Even Krishna ("dark") itself may be considered racist in today's time
Note: Now I recall that, I had observed this passage in this answer a long time back. Not sure if these 2 Qn-s can be duplicates or independent.