mesolithic age

English Thesaurus

1. middle part of the Stone Age beginning about 15,000 years ago (noun.time)

instance hypernym	:	period, period of time, time period,
definition	:	an amount of time (noun.time)

part meronym	:	stone age,
definition	:	(archeology) the earliest known period of human culture, characterized by the use of stone implements (noun.time)