拍马 is a colloquial separable verb (离合词) meaning 'to flatter' or 'to fawn on someone'. It comes from the idiom 拍马屁 (literally 'pat the horse's rear'), a historical practice of flattering by patting the horse. As a separable verb, you can insert other elements between 拍 and 马, such as a measure word or complement: 拍了一次马 ('flattered once'). The full form 拍马屁 is more common, but 拍马 alone is used in abbreviated or colloquial speech.