cram *
grind away
drum **
bone up
swot
get up ***
mug up
swot up
bone ***

Three of them are still grinding away at the localizers.

In spite of himself, he was thinking about her naked body grinding away above him.

Grinding away, as though what any of them did ever mattered.

But when they get it going again, they'll start to grind away at us.

And when that was finished what other instruments did he have to grind away at the wood with?

It continued to growl and grind away at his arm.

So she ground away at her work, never giving it up.

He already knew their plans, and no matter where they were, they'd keep grinding away at this thing.

After years of grinding away, things finally started taking off".

He didn't put in an appearance, though, so I just kept grinding away.