oka is irregularly formed from the root uc with the affix ka (a).,
The change of च् into क्, and the Guna are the irregularities. As न्योकः 'a bird, a tree'. The affix क is added under (III. I. 135). The क is added with the force of घञ् the Karaka relation being that of Location &c. The घञ् affix would have given the form regularly, but then the word would have been acutely accented on the first syllable, but it is desired that the acute should be on the last. The words दिवौकसः, जलौकसः &c are also irregular, formed with the Unadi affix असुन् the क् being substituted for च् as an Unadi diversity (bahulam).,