I. ən-ˈles, ˈən-ˌ conjunction
Etymology: Middle English unlesse, alteration of onlesse, from on + lesse less
Date: 14th century
1. : except on the condition that : under any other circumstance than
2. : without the accompanying circumstance or condition that : but that : but
II. preposition
Date: circa 1532
: except possibly : except