their
/强ðeə(r), 弱ðə(r)/possessive determiner
1
- belonging to or associated with the people or things previously mentioned or easily identified他们的; 她们的; 它们的：
parents keen to help their children.
热衷于帮助孩子们的父母。
1.1
- belonging to or associated with a person of unspecified sex（指性别不确定的人）他的; 她的：
she heard someone blow their nose loudly.
她听到有人大声地擤鼻涕。
2
Their
used in titles（用于头衔）陛下; 殿下; 阁下; 大人：a double portrait of Their Majesties.
国王和皇后陛下的双人肖像。
USAGE
On the use of their in the singular to mean 'his or her'， see usage at THEY.
词源