lead up to something: phrasal verbs

[Archanaanand]

subject : lead up to something (phrasal verb)

hello sir/madam
plz explain to me the meaning of: 1. to approach a topic of conversation , etc reluctantly or by gradual steps or stages(= approach reluctantly or by gradual steps or stages to something ). 2. to be an underlying cause of it (=be of it to something).
thanks.

[Tagarbo]

1. to approach a topic of conversation , etc reluctantly or by gradual steps or stages(= approach reluctantly or by gradual steps or stages to something ).

"to approach" a topic of conversation means to address the topic, bring it up, or introduce it to the conversation.

2. to be an underlying cause of it (=be of it to something).

If a match is the cause of the fire, then the match made (caused) the fire to occur/happen. In this case, the match is an underlying cause of the fire.

"is" is a verb form of "be"