- In the manner of a tilter; in the position, or with the
action, of one making a thrust. - In the position of a cask tilted, or with one end raised.
[In this sense sometimes used as an adjective.]
Meaning of 'atilt' (Princeton's WordNet)
1 . atilt
[ s]
Meaning (1): - departing or being caused to depart from the true vertical or horizontal