Grandmother often nods off during the afternoon.是什么意思？

Grandmother often nods off during the afternoon.

祖母下午常常打瞌睡.

grandmother

n. （外）祖母，老奶奶，女祖先；vt. 当…的祖母；vi. 当祖母；

例句
The newspaper contacted his grandmother to trace his present address, and later doorstepped him at his home.
报纸联系了他祖母，查到了他现在的住址后便前往登门采访。

often

adv. 常常，经常，时常，再三；

例句
Genetic abnormalities are more often associated with faults in paternal DNA than in maternal DNA.
相对于母本DNA,基因畸变往往更多地与父本DNA上的缺陷相关。

nods

v. 点头( nod的第三人称单数 )，打盹，打瞌睡，点头致意；

例句
Jim expression nods dully, next dodder along ground went kitchen.
吉姆神色呆滞地点了点头, 然后跌跌撞撞地去了厨房.

off

prep. 从…落下，离开，从…去掉，下班；adv. 离开，距，离，被取消，下班；adj. 不新鲜的，不能接受，不礼

例句
He eased his foot off the accelerator.
他松开了油门。

during

prep. 在…的时候，在…期间，当…之时，其间；

例句
...the accrual of funds used during construction.
建设过程中资金的累积

the

art. 指已提到的人（物），指说话人与听者已知的人（物），用于独一无二的事物前，与形容词最高级和序数词连用；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

afternoon

n. 下午，后期，后部；

例句
The afternoon was hot, sticky and airless.
那个下午闷热潮湿。