What is the meaning of أب?

father

ancestor, forefather

second-person masculine singular imperative of آبَ (ʔāba)

to put the hand to (as "to the sword")

to move, agitate

to long for one's homeland

to prepare for a journey

to intend

to be straight , upright (as a road, conduct)

to defeat

verbal noun of أَبّ (ʔabb, to intend, to prepare for a journey) 

intention

travelling plan

fodder, grass, meadow

herbage (fresh or dry)

herbage prepared for pasture

dried fruits

Alternative spelling of ابّ

not, neither, nor

father

Alternative form of أبو (ʔabu, father)

Source: wiktionary.org