The origin of this word is unclear. It is possibly derived from Proto-Indo-European *rew-, *rū-, *ru- (“to run, to rush”), via a previous adjective *runs, *rūns, on the model of brūns (“brown”), bruncis (“brown, bay horse”) (a variant of brūnis). Others have suggested that runcis is related to runa (“talk”); yet others, to rūkt (“to growl; to roar”).
runcis m (2nd declension)
- male cat, tom cat, he-cat
kad runča nav mājās, tad peles virs galda lēkā ― when the tomcat is not home, the mice jump over the table