Incontrollable

The whole struck her as so ridiculous that, despite every effort to the contrary, she burst into a fit of incontrollable laughter.

Source: tatoeba (7760439)

The whole struck her as so ridiculous that, despite every effort to the contrary, she burst into a fit of incontrollable laughter, in which she was joined by her father, though with more moderation, and finally by the Master of Ravenswood himself, though conscious that the jest was at his own expense.

Source: tatoeba (7760444)

Miss Ashton had by degrees gathered her spirits, so far as to pay some attention to what was going on; and observing the restrained impatience of Ravenswood, contrasted with the peculiar determination of manner with which Caleb detailed his imaginary banquet, the whole struck her as so ridiculous that, despite every effort to the contrary, she burst into a fit of incontrollable laughter, in which she was joined by her father, though with more moderation, and finally by the Master of Ravenswood himself, though conscious that the jest was at his own expense.

Source: tatoeba (12148596)

Set upon his will as the one law of Nature; storming forward with incontrollable violence: a very whirlwind of a man.

Source: wiktionary