loosening

höllentyminen

löysääminen (present participle of)
The act of making something looser.
2013, Michael Scott, Religious Language (page 169)

Turning to metaphor, the loosenings involved in metaphorical interpretation tend not to be pure but to involve a change that results in the extension of the loosened concept overlapping with but not including all of the denotations of the pre-loosened concept.