gr

1. abbreviationAbbreviation of grain, a unit of mass.
2. abbreviationrareAbbreviation of gram; the standard symbol for gram since the International System of Units was introduced in 1960 is g.
3. abbreviationAbbreviation of group.

1. UKabbreviationinitialismInitialism of George Rex (on coins, letterboxes, etc.) The royal cypher for George V and his son George VI, kings of Great Britain
2. abbreviationinitialismautomotiveInitialism of Gazoo Racing: A performance brand, automotive label, and, racing division, of Toyota.

plural GRs

1. abbreviationcountableinitialismuncountablebiochemistryInitialism of glucocorticoid receptor.

   1 more example

   2001 Nussey, S. S. and Whitehead, S. A. The adrenal gland. In: Bosher, Andrea. Endocrinology: An Integrated Approach. Oxford, UK: BIOS Scientific Publishers; 2001 [cited 18 December 2009]. Available from: http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=endocrin&part=A442#A468 . The expression of GR is ubiquitous and it occurs in two forms, GR-α and GR-β.

2. abbreviationcountableinitialismuncountablenatural sciencesInitialism of general relativity.
3. abbreviationcountableinitialismuncountablehobbiesInitialism of games record.