(informal) a veteran soldier, politician, or elderly person, esp one who is aggressive
Word Origin and History for warhorse
n.
1650s, "powerful horse ridden into war," from war + horse (n.). Figurative sense of "seasoned veteran" of anything is attested from 1837. In reference to women perceived as tough, by 1921.
Slang definitions & phrases for warhorse
warhorse
noun
A seasoned and reliable veteran; a grizzled doyen (1837+)