Standard Lemma guide

unlesss

conj · 1 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.

No pronunciation record was provided for this word.

1

conj

Meaning 1

Precisely unless.

Definition source: English Wiktionary via Wiktextract

Topics: human-sciences, logic, mathematics, philosophy, sciences

Examples

  • 1990, James Glimm, The Legacy of John Von Neumann, American Mathematical Society, →ISBN, page 279, Partial Order: G ≥ H unlesss (unless and only unless) H ≥ some GR or some HL ≥ G.
  • 2004, William Fraser, Susan Hirshberg, and David Wolfe, "The Structure of the Distributive Lattice of Games Born by Day n", in Integers: Electronic Journal of Combinatorial Number Theory 5(2) (2005), page 2, G ≥ H unlesss H ≥ GR or HL ≥ G for some GR ∈ GR or some HL ∈ HL. ¶ (Analogous to “iff”, the term “unlesss” means “unless and only unless”.)

Meaning relationships

Synonyms: none provided

Antonyms: none provided

History

Etymology

Attributed to John Horton Conway. From unless, by analogy with the formation of iff from if.