The term 'neuter, as a male horse' can be summarized by the crossword solution 'GELD'. Gelding is the process of surgically removing the testicles of a male horse in order to make it unable to reproduce. This procedure is often done for safety reasons, as an ungelded male horse may become aggressive and difficult to handle. Gelding is also done to reduce the cost of maintaining a horse, as gelded horses require less food and are easier to manage.