What is the origin of ambisinister?

Ambisinister, “clumsy or unskillful with both hands,” is the opposite of ambidextrous, “able to use both hands equally well.” The first element of ambisinister, ambi-, is the familiar Latin prefix ambi– “both, around,” as in ambiguous and ambivalent; the second half of the word, –sinister, comes from the Latin adjective sinister “on the left, left hand, or left side; adverse in influence or nature; unfavorably located.” Ambisinister is a relatively recent word, first recorded in 1849, more than two centuries after ambidextrous (1646).