The affix ḍupac (upa) comes in expressing diminution after the word kutū 'a jar'.,
This debars क ॥ Thus कुतुपः, from कुतू the long ऊ being elided owing to ड ॥ It means a small leathern vessel for oil. This word is neuter also, as, कुतुपम् ॥,
कुत्वा डुपच्
Adhyāya 5 · Pāda 3 · Rule 89