All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
The general statement of the scholars of Tafseer (interpretation of the Quran) about these two words is that they indicate sexual intercourse and its foreplay.
Some scholars pointed to the subtle difference in the use of the word "rafath" (to approach your wives for sexual relations) first and then the word "baashiroohunna" (have sexual relations with your wives) even though their meaning is nearly the same [in verse 187 from Soorah Al-Baqarah].
Az-Zamakhshari said in Al-Kash-shaaf:
"If you ask ‘why is it that in the first case Allah used the term "rafath" (going to your wives), which has an unpleasant connotation, contrary to His saying ... "baashiroohunna" (have sexual relations with them) … then I say that it is to disapprove of what they did before this was made lawful for them [the ruling beforehand was that it was forbidden in the night of Ramadhaan for someone to approach his wife for sex after the ‘Ishaa’ prayer, and Allah abrogated this ruling and permitted them to do so until the fajr time] and Allah called it (approaching their wives for sex after the ‘Ishaa’ prayer) deceiving themselves in the same verse."
It means that before this (intercourse after the ‘Ishaa’ in a Ramadhaan night) was made permissible for them, a man from among the Companions was allowed to eat, drink and have intercourse with his wife until he prayed the ‘Ishaa’ or slept, and if he prayed the ‘Ishaa’ or slept before he broke his fast, then eating, drinking and having intercourse with his wife became forbidden for him until the next night. Some of them violated this ruling and had intercourse with their wives after the ‘Ishaa’ prayer, so Allah disapproved of what they did and referred to it with this unpleasant word ‘rafath’ and called it deceit.
An-Nasafi, in his Tafseer, also pointed out this meaning that Az-Zamakhshari mentioned.
Allah knows best.