What is the meaning of Ob?

a halfpenny

an objection

the obese gene

observation

every other/second

Introduces an indirect question, a doubt. if, whether.

if, in case

on account of

over, above, on

in the direction of, to, towards

on account of, according to, because of, due to, for (the purpose of)

against; facing

if, whether

Alternative form of aub

two

I

Source: wiktionary.org