[mass noun]the action or fact of adopting or being adopted (被)收养 she gave up her children for adoption. 她将孩子送人收养。 the widespread adoption of agricultural technology. 农业技术的广泛采用。 [as modifier]an adoption agency. 收养中介。
语源
Middle English : from Latin adoptio(n-), from ad- 'to' + optio(n-) 'choosing' (see option)