We don't have synonyms for hilary yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are hilar, hillary and pilary.
(n) :
(UK, Ireland, law, education) Ellipsis of Hilary term. [(law) The second term of the legal year, running from January to March or April, during which the upper courts of England and Wales, and Ireland, sit to hear cases.]
(n) :
(UK, Ireland, law, education) Ellipsis of Hilary term. [(law) The second term of the legal year, running from January to March or April, during which the upper courts of England and Wales, and Ireland, sit to hear cases.]