Wordnet 3.0
NOUN (1)
1.
a person or other animal having powers of endurance or perseverance;
- Example: "the horse that won the race is a good stayer"
The Collaborative International Dictionary of English v.0.48:
Stayer \Stay"er\ (st[=a]"[~e]r), n.
One who upholds or supports that which props; one who, or
that which, stays, stops, or restrains; also, colloquially, a
horse, man, etc., that has endurance, as in a race.
[1913 Webster]
WordNet (r) 3.0 (2006):
stayer
n 1: a person or other animal having powers of endurance or
perseverance; "the horse that won the race is a good
stayer"