>"Well, 'outgrabing' is something between bellowing and whistling, with a kind of sneeze in the middle: however, you'll hear it done, maybe--down in the wood yonder--and, when you've once heard it, you'll be quite content" (Carroll The Annotated Alice 270-2).<

This still concerns me!
'outgrabing' appears to be the present participle, which would tend to make the infinitive 'outgrabe' and the present tense 'outgrabe'. So why isn't the past tense 'outgrabed'? Or 'outgrobe'?
(I cannot believe Carroll suddenly slipped into the present without noticing....)