sparring partner 
noun
1A boxer employed to engage in sparring with another as training: he had been one of Frank Bruno’s sparring partners...
- Sergio still wasn't as much of a fighter as should would have hoped for in a sparring partner, but he did manage to make things more interesting with his jabs and jokes.
- Dennis Walker, her coach and trainer since she started, often tells her to use her greatest advantage - speed - instead of standing toe-to-toe with her sparring partners.
- Right now, it seems to me that you think of other people as sparring partners, partners in crime, or players in a game that you call ‘being honest.’
1.1A person with whom one continually argues or contends: an old political sparring partner...
- Deedes is magnanimous to his old sparring partner, deemed by some accounts to be ‘a successful novelist but a failed newspaper reporter’.
- Their chemistry and timing is always spot-on, and they are completely convincing not only as verbal sparring partners but also as a married couple.
- If you're as cynical about marriage as I am, you're probably already aware how easily matrimonial bliss can deteriorate over time into a hideously spiteful and distrustful union of two diametrically opposed sparring partners.
- half mast
- half measure
- half-moon
- half-move
- half-naked
- half note
- half one (or two etc.)
- half-open
- half-pants
- half past one (or two etc.)
- half pay
- halfpenny
- halfpennyworth
- half-pie
- half-pint
- halfpipe
- half plate
- half price
- half relief
- half rest
- half-round
- half seas over
- half-sister
- half-size
- half-sized