dual
1. [ adjective ] consisting of or involving two parts or components usually in pairs
Synonyms: double duple
Examples:

"an egg with a double yolk" "a double (binary) star" "double doors" "dual controls for pilot and copilot" "duple (or double) time consists of a multiple of two beats to a measure"

Related terms: multiple
2. [ adjective ] having more than one decidedly dissimilar aspects or qualities
Synonyms: double twofold threefold treble
Examples:

"a double (or dual) role for an actor" "the office of a clergyman is twofold public preaching and private influence"- R.W.Emerson

Related terms: multiple
3. [ adjective ] (grammar) a grammatical number category referring to two items or units (as opposed to one item (singular) or more than one item (plural))
Examples:

"ancient Greek had the dual form but it has merged with the plural form in modern Greek"

Related terms: plural
Similar spelling:   duly
  dull
  Dula
  duel
  dully
  Dulle
  Duley
  Duell