Radak #1: It is what Hashem made in Shamayim, i.e. the stars. The Aleph is omitted, and also elsewhere where it is written in this Parshah.
2.
Radak #2: Some say that it is from the root Melech. It is a big star that is king over the others, i.e. the sun.
3.
Radak citing Targum Yonasan: It is the star of Heaven.
2)
Why did they say "like we and our fathers did"?
1.
Malbim: They did not worship the stars as gods. They believed in Hashem, His Hashgachah and His Nevi'im
1
. However, they thought that offering to the stars is a Segulah that helps. It is like a craft to bring down influence from the sun, which rules in Shamayim, and from it come grain and Peros.
If so, why did they not heed Yirmeyah? They saw that his Nevu'ah was fulfilled, and the promises of all the false Nevi'im were not! Perhaps they thought that he was a true Navi, but now became a false Navi, just like Chananyah ben Azur (according to Sanhedrin 90a). However, also in the past Yirmeyah told them to cease offering to the stars! This requires investigation. (PF)
3)
Why were they confident that this will bring satiation?
1.
Malbim: Experience shows that Haktarah brings an influence of dew, rain and increase of grain.
4)
Why did they say "we will be good"?
1.
Radak: We will have serenity and good.
2.
Malbim: we will be good to Hashem, for this does not contradict Elokim above. This is why [as long as we used to offer] "we did not see afflictions"!
