Karnatakabhashabhushana 7.22

Likewise for -kāra in corrupted vernacular usage.

In the domain of words derived as corrupted forms from Sanskrit, gāṟa is the substitute for the word -kāra. And the augment m [occurs] in accordance with usage.

mālegāṟaṁ [a garland-maker, from mālākāraḥ],

sammagāṟaṁ [a leather-worker, from carmakāraḥ].

Because of the mention of 'diversely', elision of the initial [consonant of the suffix] is observed in karmāra and so forth:

karmāṟaṁ [a blacksmith],

kammaṟaṁ [a blacksmith],

kumbāṟaṁ [a potter],

kumbaṟaṁ [a potter].

And likewise is the usage of Pampa in the Bhārata:

"Grabbing and lifting high the bases of the tails of two rutting elephants and crushing them, / while the blood gushing from their mouths was like an eruption of fire, / Bhīma stood like a blacksmith operating the bellows."