Idiomatic is the first foal of Lockdown (First Defence) and her first winner. Her dam is a Listed winner who was multiple Grade 1-placed and finished third in the Grade 1 Kentucky Oaks in 2017. Lockdown is a full sister to the champion Close Hatches.

Second dam Rising Tornado (Storm Cat) was a winner and has bred six winners. They include the champion Close Hatches (First Defence), who won five Grade 1 races and is the dam of two Grade 2 winners: the sire Tacitus, four times placed at Grade 1 level, and Scylla, twice Grade 1-placed.

Third dam Silver Star (Zafonic) a dual winner who finished third in the Listed Prix Coronation, has bred 11 winners, among them Barsanti (Champs Elysees), a Listed winner and second in the Gr.2 Hardwicke Stakes.

Further back this is the family of the champion Xaar (Zafonic), a dual Group 1 winner and sire.

Lockdown's unraced 4-year-old daughter Abditory (Medaglia d'Oro) has produced a first foal, a colt by Girvin, this year. The mare's last foal is the unraced 2-year-old filly Chasten (Into Mischief).