pharology
The study of lighthouses or other forms of light-signalling.
uncountable
Her previously unknown passion for pharology is shedding light on an obscure area of expertise (hobby sounds so belittling).
Where it comes from
From Latin Pharos or its source Ancient Greek Φάρος (Pháros) + -logy.
Adapted from the Wiktionary entry pharology (CC BY-SA 4.0).