Definition that contains seco
- beta second in order of importance
- subtitle secondary or explanatory title
- penultimate second last
- paleolithic 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
- palaeolithic 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
- subordinateness secondary importance
- brumaire second month of the Revolutionary calendar (October and November); the month of mist
- passion sunday second Sunday before Easter
- suprainfection secondary infection caused by an opportunistic infection
- mother's day second Sunday in May