Unless

conj.

1.

Upon any less condition than (the fact or thing stated in the sentence or clause which follows); if not; supposing that not; if it be not; were it not that; except; as, we shall fail unless we are industrious. Here nothing breeds unless the nightly owl. - Shak.

aside from, bar, barring, beside, besides, but, ex, except, except for, except that, excepting, excluding, exclusive of, if not, leaving out, let alone, omitting, outside of, precluding, save, save and except, saving, than, unless that, were it not, without