join up phrasal verbphr v a) JOIN AN ORGANIZATIONto become a member of the army, navy, or air force 参军,入伍
b) British EnglishBrE to connect things, or to become connected (使)连接join something ↔ up The dots are joined up by a line. 这些点由一条线连接起来。
join up• Most of the boys went to town to join up.• My dad joined up at the beginning of the war.• When her brothers joined up in 1914, she took over the running of the business.
→ join up at join1(8)