JAMB - Islamic Religious Knowledge Irk (2020 - No. 32)
An Hadith is referred to as da'if because
it has defects in its isnad and matn
it is a fabricated tradition
all its transmitters are reliable
it is sometimes supported with evidence
Explication
A da'if Hadith is a hadith which had defects in both its isnad and matn. Also note that a da'if hadith is one which does not fulfil the conditions of the sahih or hasan hadith.