/tɑ:(r) ||; tɑr/noun[U] 1 a thick black sticky liquid that becomes hard when it is cold. Tar is obtained from coal and is used for making roads, etc 柏油；沥青 ☞Look at Tarmac. 参看Tarmac。
2 a similar substance formed by burning tobacco 焦油: low-tar cigarettes 低焦油香烟