1. Any of various alloys of mercury with other metals, especially:
- a. An alloy of mercury and silver used in dental fillings.
- b. An alloy of mercury and tin used in silvering mirrors.
My note: (In writing and in reading we see use of this word - the second definition - used quite frequently)
troi·ka (troik) n.
1.a. A Russian carriage drawn by a team of three horses abreast. b. A team of three horses abreast.
2. See triumvirate.
My note: (I have seen this used in a writing books to describe sets of three. It's a might bit more creative than trio.)