one of the four quantities that are the basis of systems of measurement

(archeology) a period between the Stone and Iron Ages, characterized by the manufacture and use of bronze tools and weapons

(archeology) the period following the Bronze Age; characterized by rapid spread of iron tools and weapons

(archeology) the earliest known period of human culture, characterized by the use of stone implements

the earliest part of the Stone Age marked by the earliest signs of human culture

second part of the Stone Age beginning about 750,000 to 500,000 years BC and lasting until the end of the last ice age about 8,500 years BC

occurring every fourth day (especially the fever and weakness of malaria)

a period of time during which someone or something is tested

a time period during which something occurs or is expected to occur

a period of time past the deadline for fulfilling an obligation during which a penalty that would be imposed for being late is waived, especially an extended period granted as a special favor

an indefinite period of time

a period of time when something (as a machine or factory) is not operating (especially as a result of malfunctions)

(archeology) a period between the Stone and Iron Ages, characterized by the manufacture and use of bronze tools and weapons

(archeology) the period following the Bronze Age; characterized by rapid spread of iron tools and weapons

(archeology) the earliest known period of human culture, characterized by the use of stone implements

the earliest part of the Stone Age marked by the earliest signs of human culture

second part of the Stone Age beginning about 750,000 to 500,000 years BC and lasting until the end of the last ice age about 8,500 years BC