1. four-in-hand - Noun
2. four-in-hand - Adjective
Consisting of four horses controlled by one person; as, a four-in-hand team; drawn by four horses driven by one person; as, a four-in-hand coach.
A team of four horses driven by one person; also, a vehicle drawn by such a team.
Source: Webster's dictionaryfour in hand
Following his tour of the UK, he wrote about his experiences in a book entitled An American Four-in-hand in Britain. Source: Internet