-ом

Etymology 1
Reflects the principal present passive ending. Mostly unproductive in the colloquial speech, but reintroduced in the Standard language under the influence of Russian loanwords and the efforts of various "purist" movements (during the 18-20th century) for restoring grammatical features of Old Church Slavonic in Modern Bulgarian.

In rare occasions, the former participle may be fossilized as a noun, like in the case of 🇨🇬.

Suffix

 * 🇨🇬 → *пита →
 * 🇨🇬 → *пита →
 * 🇨🇬 → *пита →
 * 🇨🇬 → *пита →
 * 🇨🇬 → *пита →
 * 🇨🇬 → *пита →

Etymology 2
From or, instrumental endings of o-stem and u-stem nouns. In the modern language, derivatives constructed with this suffix are interpreted as adverbs rather than an instrumental case of the base-noun. Sometimes, adverbs from former instrumental cases further get grammatisized into interjections, as in the case of 🇨🇬 (originally meaning with God).

Related terms

 * (from yo-stem and i-stem nouns)
 * , (from a-stem nouns)