0 to think that something is true, or that what someone says is true -- يُصَدِّق
She says she’s only 30, but I don’t believe it.
Do you believe him?
1 to think something, although you are not completely sure -- يَعْتَقِد
2 used to say that something surprising is true -- صَدِّق أَو لا تُصَدِّق
He even remembered my birthday, believe it or not.
3 to be very surprised when you see someone or something, or when you hear what someone says -- لا يُصدّق عينيه / أُذُنيه