What is Abib? What does the word Abib (אביב) mean?
Let's take a look at the verses where it is mentioned:
YLT Exo 9:31 And the flax and the barley have been smitten, for the barley is budding, and the flax forming flowers,
YLT Exo 13:4 To-day ye are going out, in the month of Abib.
YLT Exo 23:15 the Feast of Unleavened things thou dost keep; seven days thou dost eat unleavened things, as I have commanded thee, at the time appointed in the month of Abib; for in it thou hast come forth out of Egypt, and ye do not appear in My presence empty;
YLT Exo 34:18 'The feast of unleavened things thou dost keep; seven days thou dost eat unleavened things, as I have commanded thee, at an appointed time, the month of Abib: for in the month of Abib thou didst come out from Egypt.
YLT Lev 2:14 'And if thou bring near a present of first-ripe fruits to Jehovah,--of green ears, roasted with fire, beaten out corn of a fruitful field thou dost bring near the present of thy first-ripe fruits,
YLT Deut 16:1 'Observe the month of Abib--and thou hast made a passover to Jehovah thy God, for in the month of Abib hath Jehovah thy God brought thee out of Egypt by night;
As you can see from the verses above, particularly Leviticus 2:14, it says to bring "Abib roasted with fire". This means that Abib means "ripe" or "ripening". You would not bring "green ears" as YLT states, because they are inedible. So Abib has to mean "ripe".
So the expression "month of Abib" should be understood as "month of ripening (of spring crops)" or more specifically a "month of flowering". In this case, it is barley and wheat.
This means that 1st month of the Year is the first month after spring equinox, because only at equinox and further the light cycle is around 12/12 hours(flowering stage), which is ideal for ripening of barley and wheat.
I hope this clarifies this word.