expression, godan verb (-su)
enter a new year; see the new year in
Refers to passing from the old year into the new one; often used when talking about where or how one spends New Year's Eve.
今年は実家で年を越すつもりです。
I plan to see the new year in at my parents' house this year.
年越し is the noun form meaning 'New Year's Eve' or 'crossing into the new year', while 年を越す is the verb phrase.
Phrase composed of 年 (year) + を (object marker) + 越す (to cross over, to pass).