From Browning's Childe Roland:
What else should he be set for, with his staff?
What, save to waylay with his lies, ensnare
All travellers who might find him posted there,
And ask the road? I guess’d what skull-like laugh
Would break, what crutch ’gin write my epitaph
For pastime in the dusty thoroughfare
What is the meaning of "crutch 'gin"? I know the meaning of crutch, but what does 'gin mean here? "Going"? "Again"? These do not seem to fit.