DCHP-2

bumps the bumps, the Bumps, the birthday bumps, the Birthday Bumps DCHP-2 (March 2016)

• n. — also the birthday bumps

  a birthday ritual where the celebrant is lifted by their arms and legs and softly lowered to the ground, once for for every year of their life.

  Type: 2. Preservation — This term describes a tradition where the birthday boy or girl is "bumped" on the ground or in the behind for every year of his or her life (see the 2009 quotation). The expression the birthday bumps is most common in the UK and in Canada (see Chart 1) (see also COD-2, s.v. "bump" (5)). As noted by the DNE, this term could derive from the dialectal British term "bump", defined as 'to take a boy by the arms and legs and knock him against a tree or post' (EDD, s.v. "bump" v.1).
  See also COD-2, s.v. "bump" (5), which is marked "Cdn & Brit. (in pl.)" and DNE, s.v. "bumps".