Definition of 当て馬 (あてうま)
あうま
                        当て馬
あてうま
ateuma
noun
1.
stallion brought close to a mare to test her readiness to mate
2.
stalking horse, spoiler
Other readings:
                あて馬【あてうま】
                Related Kanji
| 当 | hit, right, appropriate, himself | 
| 馬 | horse |