Dasakam 053 - Sloka 07

विनिघ्नति त्वय्यथ जम्बुकौघं सनामकत्वाद्वरुणस्तदानीम् । भयाकुलो जम्बुकनामधेयं श्रुतिप्रसिद्धं व्यधितेति मन्ये ॥७॥

विनिघ्नतिwhen killingत्वयि अथThou (were) thenजम्बुक-औघंthe pack of jackalsसनामकत्वात्-because of having the same nameवरुण:-तदानीम्Varuna, thenभयाकुल:out of fearजम्बुक-नाम-धेयंhis name 'Jambuka'श्रुति-प्रसिद्धं व्यधित-famous in the Vedas, hid it (in the Vedas only)इति मन्येthis I believe

Then when Thou were killing the pack of jackals, Jambukas, Varuna, the water god, whose name is famous in the Vedas as Jambuka, hid it in the Vedas only, for the fear of being killed. I believe that it is for this reason that Varuna's name as 'Jambuka' is not known.