horse chestnut vs conker

horse chestnut and conker both are nouns.

Word	Noun	Adjective	Verb	Adverb
horse chestnut	Yes	No	No	No
conker	Yes	No	No	No

As nouns, horse chestnut and conker are synonyms defined as:

horse chestnut and conker: the inedible nutlike seed of the horse chestnut

Other synonyms of horse chestnut include buckeye.

horse chestnut (noun)	conker (noun)
tree having palmate leaves and large clusters of white to red flowers followed by brown shiny inedible seeds	the inedible nutlike seed of the horse chestnut
the inedible nutlike seed of the horse chestnut