Wiktionary
crack on
vb. 1 (context intransitive idiomatic English) continue at a (normally uninteresting) task. 2 (context transitive dated English) To put on.
Usage examples of "crack on".
His voice was rising with every word, and started to crack on the high notes.
It was Baxter who uttered the cry, and not without cause, for his backbone had received a hard crack on the bottom step of the stairs.
With a convulsive shudder it threw its scimitar away, loudly shattering some window, and then slumped forward, curling as it fell to land with a crack on its head.
The door did not fit the opening well, leaving a wide crack on one side, wide enough to admit the dagger's blade.