Old Pros is a term used to refer to experienced individuals in a particular field. Vets (4 letters) is a shortened form of the word 'veterinarians', which are medical professionals who specialize in the care of animals. VETERANS (8 letters) are individuals who have served in the military, often with long-term service. ACES (4 letters) is a term used to describe someone who is highly skilled or experienced in a particular activity. All three terms can be used to refer to people who have a great deal of experience in their respective fields.