/dɒt ||; dɑt/noun[C] 1 a small, round mark, like a full stop 小圆点: a white dress with black dots 白底黑点的连衣裙The letters i and j have dots above them. 字母i和j上面有一点。
We use dot when we say a person's e-mail address. For the address ann@smithuni.co.uk we would say 'Ann at smithuni dot co dot uk'. 说某人电邮地址时使用小圆点。如ann@smithuni.co.uk这个地址可以读作ann at smithuni dot co dot uk。 2 something that looks like a dot 像圆点的东西: He watched until the aeroplane was just a dot in the sky. 他望着那飞机，直到飞机变成天空中的一颗小圆点为止。
on the dot(
informal 非正式) at exactly the right time or at exactly the time mentioned 准时:
Lessons start at 9 o'clock on the dot. 9点正开始上课。