Protective describes somebody who wants to keep another person safe and shows it. A mother stepping between her child and a strange dog, a big brother who asks who exactly you are going out with.
You are protective OF somebody: she is fiercely protective of her students. Put over- on the front and it becomes a criticism — overprotective parents who will not let a fifteen-year-old walk home in daylight. The other half of the word is physical rather than emotional: protective clothing, protective gloves, a protective layer of wax on the paintwork, all of it built to keep harm out. The verb is protect and the noun protection, and the tone shifts with the subject — warm about people, flat and technical about equipment.
1adjectiveprotectiveWanting to keep somebody safe, and acting that way.
“He is very protective of his younger sister.”
synonyms: watchful, defensive
2adjectivewornMade or worn to keep something from being damaged or harmed.
“Everyone in the workshop wears protective goggles.”
Protective was borrowed from Medieval Latin protectivus, the ready-made Latin adjective standing on the verb English already had as protect. English took the Latin form whole instead of building one of its own.
Medieval Latin
prōtēctīvus
English, today
protective
Borrowed from Medieval Latin prōtēctīvus. Borrowed from Medieval Latin prōtēctīvus. by surface analysis, protect + -ive.
Etymology from Wiktionary, CC BY-SA