I'll give you a clue:
That's right! It means FUNNEL SHAPED.
Isn't that WONDERFUL?
Now make sure you use it on every possible occasion.
"That's quite an infundibuliform figure you have there."
"I'm sorry; your argument is infundibuliform."
"Oh look Pa! The road is becoming infundibuliform!"
Note: I am not to be blamed for exploding heads or subsequent car crashes after use of the word.