Definition of grats:
(v) :
(transitive) To welcome in a friendly manner, either in person or through another means such as writing.
(v) :
(transitive) To accost; to address.
(v) :
(transitive) To arrive at or reach, or meet.
(v) :
(transitive, figurative) To be perceived by (someone).
(v) :
(intransitive, archaic) To meet and give salutations.
(v) :
(Scotland, Northern England) To weep; to cry.