Register a line, one ignored by enthusiast (7)

I believe the answer is:

almanac

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'register' is the definition.
(I've seen this before)

I don't understand the rest of the clue.

(Other definitions for almanac that I've seen before include "Calendar with astronomical data and other information" , "Calendar with detailed information" , "Sailor's or farmer's calendar" , "Statistical calendar" , "Year book with astronomical events, tides etc" .)

I've seen this clue in The Times.

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