"the relaxation of requirements"
"the loosening of his grip"
"the slackening of the wind"
the act of making something less tight
The entry of the bacteria is apparently facilitated by the loosening of the cell walls. 细胞壁松散易使细菌侵入。
Transnationalism is a social movement grown out of the heightened interconnectivity between people all around the world and the loosening of boundaries between countries. 跨国主义是一种社会性的运动，产生于全世界范围内的人之间高涨的互联性，以及国家之间的边界的松散化趋势。
Dancers were loosening up before going on stage. 舞蹈演员正在放松，准备出场。
I regulate the tempo by tightening and loosening. 节奏调控收紧和放松有高有低。