What is the meaning of 只?

An emphatic particle attached to the connective form of verbs.

The meaning of this term is uncertain. It usually appears after other verbs, taking the honorific suffix 賜 (*-si), and appears to be some kind of auxiliary. It has no known Middle Korean reflex. Nam Pung-hyeon speculates whether it might be connected to or be a variant of 在 (*KYE-).

Source: wiktionary.org