It is a negative term used to describe a person who you think is doing too much to try and please another person. For example "Michael had always supported the boss in meetings, but when he started buying the boss a cup of coffee every morning his colleagues knew that he was brown nosing." The origins of the term are a bit vulgar. Nowadays it's not really offensive, but it is slang (and therefore informal) and so you should be careful about how you use it.

Haha! This is a great question. This means to flatter or try to gain favor with someone in power. (For example, trying to become the favorite pupil of a teacher or a boss) Perhaps in arabic it is something like this: سلوك الشخص الذي يريد من المعلم أن يحبهم ، أو رئيس يحميهم. هذا تعبير سلبي. غالبًا ما نطلق على هؤلاء الأشخاص "الضفادع" أو "اللعقات الحذاء". الشخص الذي يفعل هذا ينجذب إلى الأشخاص الأقوياء. I hope this answer made sense. Good luck!