I am proofreading a doctoral thesis that has been written by a non-native English speaker (though the English level is quite high). I've never seen "ambition" used as a verb, but I did come across an article which mentioned that historically it was used as a verb with the meaning to campaign.
Here is the sentence: "(The school) ambitioned to join the local elite league and excel in the education of ‘high-achievers’".
Best Answer
The OED has a verb entry for ambition, but no examples more recent than 1881. It is in two main senses, the first of which is obsolete and doesn't appear to have been used since James I was on the throne!