accretion
n
1 [U]
(a) growth or increase by means of gradual additions (逐渐地)生长, 增大.
(b) the growing of separate things into one 连生; 合生.
2 [C]
(a) added matter that causes such growth 增添物.
(b) thing formed by the addition of such matter 积累而成的东西
a chimney blocked by an accretion of soot 被聚积的煤烟子所堵塞的烟囱.