What is the meaning of "va'Yisnav'u"?
Rashi citing Targum Yonasan: They acted crazy.
Radak: They said words of mockery that they used to say in front of Ba'al.
Malbim: They said false prophecies why it did not accept their Korban, e.g. it was angry at its worshippers.
What is "Ad La'alos ha'Minchah"?
Rashi: It is the time to offer the afternoon Korban.
Why does it say "v'Ein Kol v'Ein Oneh v'Ein Kashev"?
Shemos Rabah 29:9: Hashem silenced the entire world, upper and lower beings, as if there were no creations, for if there was a voice, they would have said that the Ba'al answered them.
Torah ha'Temimah: Chi'el did not 'answer' via making a fire (refer to 18:26:5:1).
What is the meaning of "v'Ein Kashev"?
Radak: If something was listening to them, it would have answered them. Kashev is like "v'Hikshiv Keshev Rav Kashev" (Yeshayah 21:7).
Malbim: The people did not heed their false prophecies.